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~ Constant-Q Transform in Java with TarsosDSP

The DSP library for Taros, aptly named TarsosDSP, now includes an implementation of a Constant-Q Transform (as of version 1.6). The Constant-Q transform does essentially the same thing as an FFT, but has the advantage that each octave has the same amount of bins. This makes the Constant-Q transform practical for applications processing music. If, for example, 12 bins per octave are chosen, these can correspond with the western musical scale.

Also included in the newest release (version 1.7) is a way to visualize the transform, or other musical features. The visualization implementation is done together with Thomas Stubbe.

The example application below shows the Constant-Q transform with an overlay of pitch estimations. The corresponding waveform is also shown.

Constant-Q transform in Java

Find your oven fresh baked binaries at the TarsosDSP Release Repository.
The source code can be found at the TarsosDSP GitHub repository.


~ Tarsos, a Modular Platform for Precise Pitch Analysis of Western and Non-Western Music - In Journal Of New Music Research

The journal paper Tarsos, a Modular Platform for Precise Pitch Analysis of Western and Non-Western Music by Six, Cornelis, and Leman was published in a special issue about Computational Ethnomusicology of the Journal of New Music Research on the 20th of august 2013. Below you can find the abstract for the article, and pointers to audio examples, the Tarsos software, and the author version of the article itself.

Abstract: This paper presents Tarsos, a modular software platform used to extract and analyze pitch organization in music. With Tarsos pitch estimations are generated from an audio signal and those estimations are processed in order to form musicologically meaningful representations. Tarsos aims to offer a flexible system for pitch analysis through the combination of an interactive user interface, several pitch estimation algorithms, filtering options, immediate auditory feedback and data output modalities for every step. To study the most frequently used pitches, a fine-grained histogram that allows up to 1200 values per octave is constructed. This allows Tarsos to analyze deviations in Western music, or to analyze specific tone scales that differ from the 12 tone equal temperament, common in many non-Western musics. Tarsos has a graphical user interface or can be launched using an API – as a batch script. Therefore, it is fit for both the analysis of individual songs and the analysis of large music corpora. The interface allows several visual representations, and can indicate the scale of the piece under analysis. The extracted scale can be used immediately to tune a MIDI keyboard that can be played in the discovered scale. These features make Tarsos an interesting tool that can be used for musicological analysis, teaching and even artistic productions.

To read the full text you can either download Tarsos, a Modular Platform for Precise Pitch Analysis of Western and Non-Western Music, Author version. Or obtain the published version of Tarsos, a Modular Platform for Precise Pitch Analysis of Western and Non-Western Music, published version

Ladrang Kandamanyura (slendro pathet manyura), is the name of the piece used in the article throughout section 2. The album on which the piece can be found is available at wergo. Below a thirty second fragment is embedded. You can also download the thirty second fragment to analyse it yourself.

Below the BibTex entry for the article is embedded.

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@article{six2013tarsos_jnmr,
  author = {Six, Joren and Cornelis, Olmo and Leman, Marc},
  title = {Tarsos, a Modular Platform for Precise Pitch Analysis 
            of Western and Non-Western Music},
  journal = {Journal of New Music Research},
  volume = {42},
  number = {2},
  pages = {113-129},
  year = {2013},
  doi = {10.1080/09298215.2013.797999},
 URL = {http://www.tandfonline.com/doi/abs/10.1080/09298215.2013.797999}
}

~ FMA 2013 - Computer Assisted Transcripton of Ethnic Music

At the third international workshop on Folk Music Analysis we presented a poster titled Computer Assisted Transcription of Ethnic Music]. The workshop took place in Amsterdam, Netherlands, June 6 and 7, 2013.

In the extended abstract, also titled Computer Assisted Transcription of Ethnic Music, it is described how the Tarsos software program now has features aiding transcription. Tarsos is especially practical for ethnic music of which the tone scale is not known beforehand. The proceedings of FMA 2013 are available as well.

Computer Assited Transcription of Ethnic Music poster

During the conference there also was an interesting panel on transcription. The following people participated: John Ashley Burgoyne, moderator (University of Amsterdam), Kofi Agawu (Princeton University), Dániel P. Biró (University of Victoria), Olmo Cornelis (University College Ghent, Belgium), Emilia Gómez (Universitat Pompeu Fabra, Barcelona), and Barbara Titus (Utrecht University). Some pictures can be found below.


~ TarsosLSH - Locality Sensitive Hashing (LSH) in Java

TarsosLSH is a Java library implementing Locality-sensitive Hashing (LSH), a practical nearest neighbour search algorithm for multidimensional vectors that operates in sublinear time. It supports several Locality Sensitive Hashing (LSH) families: the Euclidean hash family (L2), city block hash family (L1) and cosine hash family. The library tries to hit the sweet spot between being capable enough to get real tasks done, and compact enough to serve as a demonstration on how LSH works. It relates to the Tarsos project because it is a practical way to search for and compare musical features.

Quickly Getting Started with TarsosLSH

Head over to the TarsosLSH release repository and download the latest TarsosLSH library. Consult the TarsosLSH API documentation. If you, for some reason, want to build from source, you need Apache Ant and git installed on your system. The following commands fetch the source and build the library and example jars:

git clone https://JorenSix@github.com/JorenSix/TarsosLSH.git
cd TarsosLSH/build
ant  #Builds the core TarsosLSH library
ant javadoc #build the API documentation

When everything runs correctly you should be able to run the command line application, and have the latest version of the TarsosLSH library for inclusion in your projects. Also, the Javadoc documentation for the API should be available in TarsosLSH/doc. Drop me a line if you use TarsosLSH in your project. Always nice to hear how this software is used.

The fastest way to get something on your screen is executing this on your command line: java - jar TarsosLSH.jar this lets LSH run on a random data set. The full reference of the command line application is included below:

Name
	TarsosLSH: finds the nearest neighbours in a data set quickly, using LSH.
Synopsis    
	java - jar TarsosLSH.jar [options] dataset.txt queries.txt 
Description
	Tries to find nearest neighbours for each vector in the 
	query file, using Euclidean (L2) distance by default.
	
	Both dataset.txt and queries.txt have a similar format: 
	an optional identifier for the vector and a list of N 
	coordinates (which should be doubles).

	[Identifier] coord1 coord2 ... coordN
	[Identifier] coord1 coord2 ... coordN
	
	For an example data set with two elements and 4 dimensions:
	
	Hans 12 24 18.5 -45.6
	Jane 13 19 -12.0 49.8
	
	Options are:
	
	-f cos|l1|l2 
		Defines the hash family to use:
			l1	City block hash family (L1)
			l2	Euclidean hash family(L2)
			cos	Cosine distance hash family
	-r radius 
		Defines the radius in which near neighbours should
		be found. Should be a double. By default a reasonable
		radius is determined automatically.
	-h n_hashes
		An integer that determines the number of hashes to 
		use. By default 4, 32 for the cosine hash family.
	-t n_tables
		An integer that determines the number of hash tables,
		each with n_hashes, to use. By default 4.
	-n n_neighbours
		Number of neighbours in the neighbourhood, defaults to 3.
	-b 
		Benchmark the settings. 
	--help 
		Prints this helpful message.
Examples
	Search for nearest neighbours using the l2 hash family with a radius of 500
	and utilizing 5 hash tables, each with 3 hashes.
	
	java - jar TarsosLSH.jar -f l2 -r 500 -h 3 -t 5 dataset.txt queries.txt

Source Code Organization

The source tree is divided in three directories:

Further Reading

This section includes a links to resources used to implement this library.


~ Spotify Music Quiz - With a Big Red Button

This post documents how to implement a simple music quiz with the meta data provided by Spotify and a big red button.

During my last birthday party, organized at Hackerspace Ghent ,there was an ongoing Spotify music quiz. The concept was rather simple: If music that was playing was created in the same year as I was born, the guests could press a big red button and win a price! If they guessed incorrectly, they were publicly shamed with a sad trombone. Only one guess for each
song was allowed.

Below you can find a small videograph which shows the whole thing in action. The music quiz is simple: press the button if the song is created in 1984. In the video, at first a wrong answer is given, then a couple of invalid answers follow. Finally a good answer is given, the song “The Killing Moon by Echo & the Bunnymen” is from 1984! Woohoo!

Allright, what did I use to to implement the spotify music quiz:

The Red Button

A nice big red button, which main features are that it is red and big, serves as the main input device for the quiz. To be able to connect the salvaged safety button to a computer via USB, an Arduino Nano is used. The Arduino is loaded with the code from the debounce tutorial, basically unchanged. Unfortunately, I could not fit the the FTDI-chip, which provides the USB connection, in the original enclosure. An additional enclosure, the white one seen in the pictures below, was added.

When pressed, the button sends a signal over the serial line. See below how the Ruby Quiz script waits for, and handles such event.

Get Meta Data from the Currently Playing Song in Spotify

Another requirement for the quiz to work is the ability to get information about the song currently playing in Spotify. On Linux this can be done with the dbus interface for Spotify. The script included below returns information about the artist, album and title of the song. It also detects if Spotify is running or not. Find it, fork it, use it, on github

On Mac OS X, Spotify can be controlled using AppleScript. A script on github shows how to get meta data about the currently playing song in Spotify, on Mac OS X.

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#!/usr/bin/python
#
# now_playing.py
# 
# Python script to fetch the meta data of the currently playing
# track in Spotify. This is tested on Ubuntu.
 
import dbus
bus = dbus.SessionBus()
try:
  spotify = bus.get_object('com.spotify.qt', '/')
  iface = dbus.Interface(spotify, 'org.freedesktop.MediaPlayer2')
  meta_data = iface.GetMetadata()
  artistname = ",".join(meta_data['xesam:artist'])
  trackname = meta_data['xesam:title']
  albumname = meta_data['xesam:album']
  #Other fields are:
  # 'xesam:trackNumber', 'xesam:discNumber','mpris:trackid',
  # 'mpris:length','mpris:artUrl','xesam:autoRating','xesam:contentCreated','xesam:url'
  print str(trackname + " | " + artistname + " | " + albumname + " | Unknown")
except dbus.exceptions.DBusException:
  print "Spotify is not running."

The Quiz Ruby Script

With the individual part in order, we now need Ruby glue to paste it all together. The complete music quiz script can be found on github. The main loop, below, waits for a button press. If it is pressed the sad trombone, invalid answer or winner sound is played. The sounds are attached to this post.

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while true do
  # Wait for a button press
  data = sp.readline
  # Fetch meta data about the currently
  # playing song
  result = `#{now_playing_command}`
  # Parse the meta data
  title,artist,album = parse_result(result)
  #Title is hash key, should be unique within playlist
  key = title
  if responded_to.has_key? key
    puts "Already answered: you cheater"
    play cheater
  elsif correct_answers.has_key? key
    puts "Correct answers: woohoo"
    responded_to[key]=true
    play winner
  else
    puts "Incorrect answer: sad trombone"
    responded_to[key]=true
    play sad_trombone
  end
end

~ Flanger Audio Effect in Java

The DSP library for Taros, aptly named TarsosDSP, now includes an example demonstrating the flanging audio effect. Flanging, essentialy mixing the signal with a varying delay of itself, produces an interesting interference pattern.

Pitch estimation synthesizer

The flanging example works on wav-files or on input from microphone. Try it yourself, download
Flanging.jar, the executable jar file. Below you can check what flanging sounds like with various parameters.

The source code of the Java implementation can be found on the TarsosDSP github page.


~ TarsosDSP Christmas Edition: Jingle Cats

The DSP library for Taros, aptly named TarsosDSP, now includes an example showing how to synthesize cat sounds. The inspration came from this youtube video

To hear what exactly it does, listen to the following audio example.

There is also a command line interface, the following command does

java -jar Catify-latest.jar in.mid

 _______                       _____   _____ _____  
|__   __|                     |  __ \ / ____|  __ \ 
   | | __ _ _ __ ___  ___  ___| |  | | (___ | |__) |
   | |/ _` | '__/ __|/ _ \/ __| |  | |\___ \|  ___/ 
   | | (_| | |  \__ \ (_) \__ \ |__| |____) | |     
   |_|\__,_|_|  |___/\___/|___/_____/|_____/|_|     
                                                    
----------------------------------------------------
Name:
	TarsosDSP catify'er
----------------------------------------------------
Synopsis:
	java -jar Catify-latest.jar input.mid
----------------------------------------------------
Description:
	

The source code of the Java implementation of the catify’er can be found on the TarsosDSP github page.


~ TarsosDSP Pitch Estimation Synthesizer

The DSP library for Taros, aptly named TarsosDSP, now includes an example showing how to synthesize pitch estimations. The goal of the example is to show which errors are made by different pitch detectors.

Pitch estimation synthesizer

To test the application, download and execute the Resynthesizer.jar file and load an audio file. For the moment only 44.1kHz mono wav is allowed. To hear what exactly it does, compare the following two audio fragments:


There is also a command line interface, the following command does pitch tracking, and follows the envelope of in.wav and immediately plays it on the default audio device. If you want to save the audio, see the command line options. The flute example is provided for your convenience.

java -jar Resynthesizer-latest.jar in.wav

 _______                       _____   _____ _____  
|__   __|                     |  __ \ / ____|  __ \ 
   | | __ _ _ __ ___  ___  ___| |  | | (___ | |__) |
   | |/ _` | '__/ __|/ _ \/ __| |  | |\___ \|  ___/ 
   | | (_| | |  \__ \ (_) \__ \ |__| |____) | |     
   |_|\__,_|_|  |___/\___/|___/_____/|_____/|_|     
                                                    
----------------------------------------------------
Name:
	TarsosDSP resynthesizer
----------------------------------------------------
Synopsis:
	java -jar CommandLineResynthesizer.jar [--detector DETECTOR] [--output out.wav] [--combined combined.wav] input.wav
----------------------------------------------------
Description:
	Extracts pitch and loudnes from audio and resynthesises the audio with that information.
	The result is either played back our written in an output file. 
	There is als an option to combine source and synthezized material
	in the left and right channels of a stereo audio file.


	input.wav		a readable wav file.

	--output out.wav		a writable file.

	--combined combined.wav		a writable output file. One channel original, other synthesized.
	--detector DETECTOR	defaults to FFT_YIN or one of these:
				YIN
				MPM
				FFT_YIN
				DYNAMIC_WAVELET
				AMDF


The source code of the Java implementation of the synthesizer can be found on the TarsosDSP github page.


~ Phase Vocoding: Time Stretching and Pitch Shifting with TarsosDSP Java

The DSP library for Taros, aptly named TarsosDSP, now includes an implementation of a pitch shifting algorithm (as of version 1.4) and a time stretching algorithm. Combined, the two can be used for something like phase vocoding. With a phase vocoder you can load an audio snippet, change the pitch and duration and e.g. create a library of snippets. E.g. by recording one piano key stroke, it is possible to generate two octaves of samples of different lengths, and use those in stead of synthesized samples. The following example application shows exactly that, implemented in the java programming language.

The example application below shows how to pitch shift and time stretch a sample to create a sample library with the TarsosDSP library.

Pitch shifting in Java

Find your oven fresh baked binaries at the TarsosDSP Release Repository.


~ Tarsos 1.0: Transcription Features

Today marks the reslease of Tarsos 1.0 . The new Tarsos release contains practical transcription features. As can be seen in the screenshot below, a time stretching feature makes it easy to loop a certain audio fragment while it is playing in a slow tempo. The next loop can be played with by pressing the n key, the one before by pressing b.

Since the pitch classes can be found in a song, and there is a feature that lets you play a MIDI keyboard in the tone scale of the song under analysis, transcription of ethnic music is made a lot easier.


Tarsos 1.0

The new release of Tarsos can be found in the Tarsos release repository. From now on, nightly releases are uploaded there automatically.


~ Pitch Shifting - Implementation in Pure Java with Resampling and Time Stretching

The DSP library for Taros, aptly named TarsosDSP, now includes an implementation of a pitch shifting algorithm (as of version 1.4). The goal of pitch shifting is to change the pitch of a piece of audio without affecting the duration. The algorithm implemented is a combination of resampling and time stretching. Resampling changes the pitch of the audio, but affects the total duration. Consecutively, the duration of the audio is stretched to the original (without affecting pitch) with time stretching. The result is very similar to phase vocoding.

The example application below shows how to pitch shift input from the microphone in real-time, or pitch shift a recorded track with the TarsosDSP library.

Pitch shifting in Java

To test the application, download and execute the PitchShift.jar file and load an audio file. For the moment only 44.1kHz mono wav is allowed. To get started you can try this piece of audio.

There is also a command line interface, the following command lowers the pitch of in.wav by two semitones.

java -jar in.wav out.wav -200

----------------------------------------------------
 _______                       _____   _____ _____  
|__   __|                     |  __ \ / ____|  __ \ 
   | | __ _ _ __ ___  ___  ___| |  | | (___ | |__) |
   | |/ _` | '__/ __|/ _ \/ __| |  | |\___ \|  ___/ 
   | | (_| | |  \__ \ (_) \__ \ |__| |____) | |     
   |_|\__,_|_|  |___/\___/|___/_____/|_____/|_|     
                                                    
----------------------------------------------------
Name:
	TarsosDSP Pitch shifting utility.
----------------------------------------------------
Synopsis:
	java -jar PitchShift.jar source.wav target.wav cents
----------------------------------------------------
Description:
	Change the play back speed of audio without changing the pitch.

		source.wav	A readable, mono wav file.
		target.wav	Target location for the pitch shifted file.
		cents		Pitch shifting in cents: 100 means one semitone up, 
				-100 one down, 0 is no change. 1200 is one octave up.

The resampling feature was implemented with libresample4j by Laszlo Systems. libresample4j is a Java port of Dominic Mazzoni’s libresample 0.1.3, which is in turn based on Julius Smith’s Resample 1.7 library.


~ ISMIR 2012 - Highlights

Logo ISMIR 2012The 13th International Society for Music Information Retrieval Conference took place in Porto, Portugal, October 8th-12th, 2012. This text contains links to some papers, toolkits, software presented there which are interesting for my research. Basically it contains my personal highlights of the conference. The ISMIR 2012 is described as follows:

The annual Conference of the International Society for Music Information Retrieval (ISMIR) is the world’s leading research forum on processing, searching, organizing and accessing music-related data. The revolution in music distribution and storage brought about by digital technology has fueled tremendous research activities and interests in academia as well as in industry. The ISMIR Conference reflects this rapid development by providing a meeting place for the discussion of MIR-related research, developments, methods, tools and experimental results. Its main goal is to foster multidisciplinary exchange by bringing together researchers and developers, educators and librarians, as well as students and professional users.

Tutorials

I saw an interesting tutorial on Jazz music and a tutorial on source separation. After an introduction, which detailed the experimental basis of the system, a source separator was introduced. The REPET source separator is a relatively simple system that yields reasonable results to split accompaniment from foreground melody.

Posters & Talks

The approach and the dataset used in N-gram Based Statistical Makam Detection on Makam Music in Turkey Using Symbolic Data is very interesting. More than 800 pieces of makam music where transcribed manually and analysed. Details about the dataset are available in the following paper: A Turkish Makam Music Symbolic Database for Music Information Retrieval: SymbTr.

Assigning a Confidence Threshold on Automatic Beat Annotation in Large Datasets by Zapata et al. shows a very interesting way to do exactly what the title says. Descriptive titles are descriptive.

A very practical tool to do melody extraction was presented by Justin Salamon. He created a Vamp Plugin with the name Melodia. Unfortunately the plugin is currently only available for windows, but Linux and OS X versions are in the pipeline. More about the algorithm implemented and background information can be found in the paper Justin presented: Statistical Characterisation of Melodic Pitch Contours and its Application for Melody Extraction. Another Vamp Plugin for melody visualization was also presented: Pitch Content Visualization Tools for Music Performance Analysis.

The ongoing work by Ceril Bohak and Matija Marolt on segmentation of folk music could be very useful to apply on Afican musics. The paper is called Finding Repeating Stanzas in Folk Songs.


~ CIM 2012 - Revealing and Listening to Scales From the Past; Tone Scale Analysis of Archived Central-African Music Using Computational Means

Logo Universiteit UtrechtWhat follows is about the Conference on Interdisciplinary Musicology and the 15th international Conference of the Gesellschaft fur Musikfoschung. First this text will give information about our contribution to CIM2012: Revealing and Listening to Scales From the Past; Tone Scale Analysis of Archived Central-African Music Using Computational Means and then a number of highlights of the conference follow. The joint conference took place from the 4th to the 8th of september 2012.

In 2012, CIM will tackle the subject of History. Hosted by the University of Göttingen, whose one time music director Johann Nikolaus Forkel is widely regarded as one of the founders of modern music historiography, CIM12 aims to promote collaborations that provoke and explore new methods and methodologies for establishing, evaluating, preserving and communicating knowledge of music and musical practices of past societies and the factors implicated in both the preservation and transformation of such practices over time.

Revealing and Listening to Scales From the Past; Tone Scale Analysis of Archived Central-African Music Using Computational Means

Our contribution ton CIM 2012 is titled Revealing and Listening to Scales From the Past; Tone Scale Analysis of Archived Central-African Music Using Computational Means. The aim was to show how tone scales of the past, e.g. organ tuning, can be extracted and sonified. During the demo special attention was given to historic Central African tuning systems. The presentation I gave is included below and or available for download

Highlights

What follows are some personal highlights for the Conference on Interdisciplinary Musicology and the 15th international Conference of the Gesellschaft fur Musikfoschung. The joint conference took place from the 4th to the 8th of september 2012.

The work presented by Rytis Ambrazevicius et al. Modal changes in traditional Lithuanian singing: Diachronic aspect has a lot in common with our research, it was interesting to see their approach. Another highlight of the conference was the whole session organized by Klaus-Peter Brenner around Mbira music.

Rainer Polak gave a talk titled ‘Swing, Groove and Metre. Asymmetric Feels, Metric Ambiguity and Metric Transformation in African Musics’. He showed how research about rhythm in jazz research, music theory and empirical musicology ( amongst others) could be bridged and applied to ethnic music.

The overview Eleanore Selfridge-Field gave during her talk Between an Analogue Past and a Digital Future: The Evolving Digital Present was refreshing. She had a really clear view on all the different ways musicology and digital media can benifit from each-other.

From the concert programme I found two especially interesting: the lecture-performance by Margarete Maierhofer-Lischka and Frauke Aulbert of Lotofagos, a piece by Beat Furrer and Burdocks composed and performed by Christian Wolff and a bunch of enthusiastic students.


~ ICMC 2012 - Sound to Scale to Sound, a Setup for Microtonal Exploration and Composition

Logo Universiteit UtrechtAt this years ICMC Conference, ICMC 2012 we presented a paper describing a way to experiment with tone scales and how to use Tarsos as a compositional tool. What follows are some pointers to the presentation, paper and to other interesting talks that were presented there.

ICMC 2012 was organized in Ljubljana from the 9 to 14 septembre and had a very dense program of talks, posters, presentations, demos and concerts.

Since 1974 the International Computer Music Conference has been the major international forum for the presentation of the full range of outcomes from technical and musical research, both musical and theoretical, related to the use of computers in music. This annual conference regularly travels the globe, with recent conferences in the Americas, Europe and Asia. This year we welcome the conference to Slovenia for the first time.

Sound to Scale to Sound, a Setup for Microtonal Exploration and Composition

Our contribution to the conference was a paper titled Sound to Scale to Sound, a Setup for Microtonal Exploration and Composition.

If you want to cite our work, this BibTeX entry is included for your convenience:

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@inproceedings{cornelis2012sound_to_scale,
  author     = {Olmo Cornelis and Joren Six},
  title      = {{Sound to Scale to Sound, a Setup for Microtonal Exploration and Composition}},
  booktitle  = {{Proceedings of the 2012 International Computer Music Conference,
               (ICMC 2012)}},
  year       = {2012},
  publisher = {The International Computer Music Association}
}

Program highlights

What follows are a number of pointers to my personal program highlights.

Verena Thomas presented two very well polished software tools. One to detect patterns in scores, called motifviewer and a tool to search in score databases in a multi-modal way. The Probado tool does score-to-audio alignment and much more.

Gibber is an impressive live-coding environment with an easy syntax. Since it is all done with javascript you can start playing with it immediately. Overtone Another live-coding environment, presented at the conference by Sam Aaron, was equally impressive. It is programmed using the Closure language.

At ICMC there were a number of tools to assist in composition. One of those is The Bach Project, by Andrea Agostini. Togheter with CatART by Diemo Swartz it forms a very expressive platform to work with sound, which was demonstrated by Aaron Einbond and Christopher Trapani in their paper titled Precise Pitch Control In Real Time Corpus-Based Concatenative Synthesis. Diemo Swartz presented work on Audio Mosaicing, it can be seen as a follow-up to AuidioGuild by Ben Hackbarth.

I also got to know the work by Thomas Grill, on his website a nice piece of software can be found a Python implementation of the Non Stationary Gabor Transform. Another software system I got to know is the functional signal processing programming language FAUST

My personal highlights of the concert programme include the works by Johannes Kreidler, Aura Pon, Daniel Mayer, Alexander Schubert and the remarkable performance by Dexter Ford. The concept behind Soundlog by Johannes Kretz was also interesting.


~ Analytical Approaches To World Music - Microtonal Scale Exploration in Central Africa

At the 2012 AAWM conference we presented a way to explore tone scales in the music of Central Africa. Since the audience consisted of (ethno)musicologists, the main focus of the presentation was on the applicication part, the technical aspects were only briefly mentioned.

The extended abstract can be consulted: Towards the tangible: microtonal scale exploration in Central-African music

The conference program itself was very diverse and interesting.


~ TarsosDSP Release 1.2

Today a new version of the TarsosDSP library was released. TarsosDSP is a small library to do audio processing in Java. It features two new pitch detectors. An AMDF pitch detector, contributed by Eder Souza of Brazil and a faster implementation of YIN kindly provided by Matthias Mauch of Queen Mary University, London.

Pitch Detector in Java

Find your oven fresh baked binaries at the TarsosDSP Release Repository.


~ Guest Lecture at MIT - Ethnic Music Analysis: Challenges & Opportunities - Tarsos as a Case Study

Thursday the 3th of May I gave a guest lecture titled ‘Ethnic Music Analysis: Challenges & Opportunities’ it featured Tarsos as a Case Study. The goal was to identify the difficulties when dealing with ethnic music and to show a possible approach, the approach implemented by Tarsos.

The invitation to give the guest lecture came from Michael Cuthbert who is one of the driving forces behind music21. The audience was a small group of double majors in both musicology and computer science: the ideal profile to gather useful feedback.


~ TarsosDSP Release 1.0

After about a year of development and several revisions TarsosDSP has enough features and is stable enough to slap the 1.0 tag onto it. A ‘read me’, manual, API documentation, source and binaries can be found on the TarsosDSP release directory. The source is present in the
What follows below is the information that can be found in the read me file:

TarsosDSP is a collection of classes to do simple audio processing. It features an implementation of a percussion onset detector and two pitch detection algorithms: Yin and the Mcleod Pitch method. Also included is a Goertzel DTMF decoding algorithm and a time stretch algorithm (WSOLA).

Its aim is to provide a simple interface to some audio (signal) processing algorithms implemented in pure JAVA. Some TarsosDSP example applications are available.

The following example filters a band of frequencies of an input file testFile. It keeps the frequencies form startFrequency to stopFrequency.

AudioInputStream inputStream = AudioSystem.getAudioInputStream(testFile);
AudioDispatcher dispatcher = new AudioDispatcher(inputStream,stepSize,overlap);
dispatcher.addAudioProcessor(new HighPass(startFrequency, sampleRate, overlap));
dispatcher.addAudioProcessor(new LowPassFS(stopFrequency, sampleRate, overlap));
dispatcher.addAudioProcessor(new FloatConverter(format));
dispatcher.addAudioProcessor(new WaveformWriter(format,stepSize, overlap, "filtered.wav"));
dispatcher.run();

Quickly Getting Started with TarsosDSP

Head over to the TarsosDSP release repository and download the latest TarsosDSP library. To get up to speed quickly, check the TarsosDSP Example applications for inspiration and consult the API documentation. If you, for some reason, want to build from source, you need Apache Ant and git installed on your system. The following commands fetch the source and build the library and example jars:

git clone https://JorenSix@github.com/JorenSix/TarsosDSP.git
cd TarsosDSP/build
ant tarsos_dsp_library #Builds the core TarsosDSP library
ant build_examples #Builds all the TarsosDSP examples
ant javadoc #Creates the documentation in TarsosDSP/doc

When everything runs correctly you should be able to run all example applications and have the latest version of the TarsosDSP library for inclusion in your projects. Also the Javadoc documentation for the API should be available in TarsosDSP/doc. Drop me a line if you use TarsosDSP in your project. Always nice to hear how this software is used.

Source Code Organization and Examples of TarsosDSP

The source tree is divided in three directories:


~ Text to Speech to Speech Recognition - Am I Sitting in a Room?

This post is about a hack I did for the 2012 Amsterdam music hack days. From the website:

The Amsterdam Music Hack Day is a full weekend of hacking in which participants will conceptualize, create and present their projects. Music + software + mobile + hardware + art + the web. Anything goes as long as it’s music related

The hackathon was organized at the NiMK(Nederlands instituut voor Media Kunst) the 25th and 24th of May. My hack tries to let a phone start a conversation on its own. It does this by speaking a text and listening to the spoken text with speech recognition. The speech recognition introduces all kinds of interesting permutations of the original text. The recognized text is spoken again and so a dreamlike, unique nonsensical discussion starts. It lets you hear what goes on in the mind of the phone.

The idea is based on Alvin Lucier’s I am Sitting in a Room form 1969 which is embedded below. He used analogue tapes to generate a similar recursive loop. It is a better implementation of something I did a couple of years ago.

The implementation is done with Android and its API’s. Both speech recognition and text to speech are available on android. Those API’s are used and a user interface shows the recognized text. An example of a session can be found below:

To install the application you can download Tryalogue.apk of use the QR-code below. You need Android 2.3 with Voice Recognition and TTS installed. Also needed is an internet connection. The source is also up for grabs.


~ Oscilloscope in TarsosDSP

The DSP library for Taros, aptly named TarsosDSP, now includes an implementation of an oscilloscope.

Oscilloscope in Java

The source code of the Java implementation can be found on the TarsosDSP github page. That is all.


Previous blog posts

08-03-2012 ~ Dan Ellis' Robust Landmark-Based Audio Fingerprinting - With Octave

02-03-2012 ~ Harmony and Variation in Music Information Retrieval

23-02-2012 ~ Echo or Delay Audio Effect in Java With TarsosDSP

14-02-2012 ~ Spectrogram in Java with TarsosDSP

10-02-2012 ~ Démonstration de Tarsos

06-02-2012 ~ Audio Time Stretching - Implementation in Pure Java Using WSOLA

03-02-2012 ~ Tarsos CLI: Detect Pitch

17-01-2012 ~ A Robust Audio Fingerprinter Based on Pitch Class Histograms - Applications for Ethnic Music Archives

21-12-2011 ~ Pitch, Pitch Interval, and Pitch Ratio Representation

15-12-2011 ~ TarsosDSP sample application: Utter Asterisk

12-12-2011 ~ TarsosDSP used in jAM - Java Automatic Music Transcription

12-12-2011 ~ Kinderuniversiteit - Muziek onder de microscoop!

07-12-2011 ~ How To: Generate an Audio Fingerprinting Data Set With Sox Audio Effects

06-12-2011 ~ The Power of the Pentatonic Scale

02-12-2011 ~ Software for Music Analysis

09-11-2011 ~ Robust Audio Fingerprinting with Tarsos and Pitch Class Histograms

09-11-2011 ~ PeachNote Piano demo at ISMIR 2011

25-10-2011 ~ Tarsos at 'Study Day: Tuning and Temperament - Insitute of Musical Research, London'

25-10-2011 ~ Tarsos presentation at 'ISMIR 2011'

18-10-2011 ~ Tarsos at 'WASPAA 2011'