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~ Pitch, Pitch Interval, and Pitch Ratio Representation

To prevent confusion about pitch representation in general and pitch representation in Tarsos specifically I wrote a document about pitch, pitch Interval, and pitch ratio representation. The abstract goes as follows:

This document describes how pitch can be represented using various units. More specifically it documents how a software program to analyse pitch in music, Tarsos, represents pitch. This document contains definitions of and remarks on different pitch and pitch interval representations. For good measure we need a definition of pitch, here the definition from [McLeod 2009] is used: The pitch frequency is the frequency of a pure sine wave which has the same perceived sound as the sound of interest. For remarks and examples of cases where the pitch frequency does not coincide with the fundamental frequency of the signal, also see [McLeod 2009] . In this text pitch, pitch interval and pitch ratio are briefly discussed.

~ TarsosDSP sample application: Utter Asterisk

Uttter AsteriskThe DSP library of Tarsos, aptly named TarsosDSP, contains an implementation of a game that bares some resemblance to SingStar. It is called UtterAsterisk. It is meant to be a technical demonstration showing real-time pitch detection in pure java using a YIN -implementation.

Download Utter Asterisk and try to sing (utter) as close to the melody as possible. The souce code for Utter Asterisk is available on github.

~ TarsosDSP used in jAM - Java Automatic Music Transcription

jAM logoTarsosDSP, a small Java DSP library, has been used in a bachelor thesis: Entwicklung eines Systems zur automatischen Notentranskription von monophonischem Audiomaterial by Michael Wager.

The goal of the thesis was to develop an automatic transcription system for monophonic music. You can download the latest version of jAM – Java Automatic Music Transcription.

If you want to use TarsosDSP, please consult the TarsosDSP page on github or read more about TarsosDSP here.

~ Kinderuniversiteit - Muziek onder de microscoop!

Zondag 18 december 2011 gaf ik een workshop voor de Gentse kinderuniversiteit. Het thema van de kinderuniversiteit was Muziek onder de microscoop. De teaser voor de workshop is hier te vinden:

Logo kinderuniversiteitWORKSHOP – Muziek (ont)luisteren op de computer
Is het mogelijk om piano te spelen op een tafel? Kan een computer luisteren naar muziek en er van genieten? Wat is muziek eigenlijk, en hoe werkt geluid?
Tijdens deze workshop worden de voorgaande vragen beantwoord met enkele computerprogramma’s!

Concreet worden enkele componenten van geluid (en bij uitbreiding, muziek) gedemonstreerd met computerprogrammaatjes gemaakt in het conservatorium:

De foto’s hieronder geven een sfeerbeeld.

~ How To: Generate an Audio Fingerprinting Data Set With Sox Audio Effects

A small part of Tarsos has been turned into a audio fingerprinting application. The idea of audio fingerprinting is to create a condensed representation of an audio file. A perceptually similar audio file should generate similar fingerprints. To test how robust a fingerprinting technique is, a data set with audio files that are alike in some way is practical.

SoX – Sound eXchange is a command line utility for sound processing. It can apply audio effects to a sound. Using these effects and a set of unmodified songs an audio fingerprinting data set can be created. To generate such a data set SoX can be used to:

#Trim the first 10 seconds
sox input.wav output.wav trim 10

#speed-up of 10%
sox input.wav output.wav speed 1.10

#change the pitch upwards 100 cents (one semitone)
#without changing the tempo
sox input.wav output.wav pitch 100

#generate white noise with the length of input.wav
sox input.wav noise.wav synth whitenoise
#mix the white noise with the input to generate noisy output
#-v defines how loud the white noise is
sox -m input.wav -v 0.1 noise.wav output.wav

#reverse the audio
sox input.wav output.wav reverse

A ruby script to generate a lot of these files can be found attached.

~ The Power of the Pentatonic Scale

The following video shows Bobby McFerrin demonstrating the power of the pentatonic scale. It is a fascinating demonstration of how quickly a (western) audience of the World Science Festival 2009 adapts to an unusual tone scale:

With Tarsos the scale used in the example can be found. This is the result of a quick analysis: it becomes clear that this, in fact, a pentatonic scale with an unequal octave division. A perfect fifth is present between 255 and 753 cents:

A pentatonic scale, demonstrated by Bobby McFerrin

~ Software for Music Analysis

Friday the second of December I presented a talk about software for music analysis. The aim was to make clear which type of research topics can benefit from measurements by software for music analysis. Different types of digital music representations and examples of software packages were explained.

software for music analysis

Following presentation was used during the talk. (ppt, odp):

To show the different digital representations of music one example (Liebestraum 3 by Liszt) was used in different formats: