Computational modeling for

Hindustani music

Preeti Rao

Department of Electrical Engineering

Indian Institute of Technology Bombay

CompMusic Workshop, January, 2012,

KIIT College of Engineering, Gurgaon 1

Topics Covered

• What we can do with our computing tools…

• Why it may be useful to

– Musicological studies

– Pedagogy

– Access and enjoyment of music

2

500

0.2

1000-0.4

0

0.5

50

( )tx3

)(mst

)(Hzf

( )fX 3

Sounds of music: complex tone signal

Department of Electrical

Engineering , IIT Bombay

Sound and Sensation

Primary sensations Physical correlates

– loudness intensity

– pitch fundamental frequency

– timbre (“quality” ) spectro-temporal properties

Music conceptsBasic dimensions of music are melody, rhythm, harmony

and timbre.

• Melody, harmony -> based on pitch content

• Rhythm -> based on timing information

• Timbre -> relates to instrumentation, texture

A representation of these high-level attributes can be

obtained from pitch and timing information extracted by

audio signal analysis.

5

Melodic Pitch Contours• Differences in the two melodic styles are observed by the

visual comparison of the pitch contour segments

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Pitch contour of alaap segments of Carnatic vocalist Nagavalli Nagaraj for raagSubhapanthuvarali. The y-axis denotes the pitch in cents with respect to the A-440Hz.

Discrete notes?

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Melodic contour: applications

• Musicological studies such as intonation

• Melodic phrase matching for pedagogy: both for “emulation” and improvisation.

• Melodic similarity for music classification and retrieval including visualization.

• Transcription to aid studies deriving from symbolic notation of music

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• Intonation (shruti is all important. Should be

accurate for given raga, style…….)

• Pitch class distributions (past work)

FRSM 2012 - 18-19 January, 2012, KIIT

College of Engineering, Gurgaon9

Ornamentation• Style, emotions, gharana (school/style) characteristics,

raga characteristics and even the personal characteristics influence the ornaments.

• Ornaments enhance the basic melodic contour and contribute to musicality/ expressiveness.

e.g. grace note, a glide between two notes, multiple oscillations of a single note, oscillation between notes….

• Of the ornaments, those that are often transcribed in notation are Meend, Andolan, Khatka, Murki, Gamak, Zamzama

[ITC SRA site: http://www.itcsra.org/alankar/alankar.html]

June 20th, 2011 DAP Lab., Dept. of EE 10 of 50

Visualization and pedagogy

DAP Lab., Dept. of EE

Model

Singer

Trained

Singer

Amateur

Singer

Time (sec)

Pitch

Fre

qu

en

cy(H

z)

Fre

qu

en

cy(H

z)

11 of 50June 20th, 2011

Observed differences

DAP Lab., Dept. of EE

• The “notes” rendered by both, trained and

amateur singers, are similar to the reference

• The differences lie between the notes…

Model Singer Trained Singer Amateur Singer

Gamak: Oscillations-on-Glide

• Periodic oscillations riding on a glide-like transition from one note to another (may or may not be of uniform amplitude)

• Gamak in Indian classical music as defined in [SRAsite] : “A gamak can be defined as a fast meend (spanning 2-3 notes normally) delivered with deliberate force and vigor and repeated in an oscillatory manner”

• Possible attributes:

– Glide - overall monotonic trend

– Oscillation - pure vibration around

the glide

• Amplitude

• Rate

DAP Lab., Dept. of EE 13 of 50

0 0.1 0.2 0.3 0.4-400

-300

-200

-100

0

100

200

300

Time (sec)

Pitch F

req (

cents

)

Objective measure: distance in parameter space...

0 20 40 60 80 100 1200

0.2

0.4

0.6

0.8

1

Singers

Ho

listic O

bje

ctiv

e S

co

re

Good

Medium

Bad

14 of 50

Correlation with perceived quality

[C. Gupta and P. Rao, "An objective evaluation tool for ornamentation in singing",

Proc. of International Symposium on Computer Music Modeling and Retrieval

(CMMR) and Frontiers of Research on Speech and Music (FRSM), 2011.]

F. Gouyon, S. Dixon

ISMIR 2006 Tutorial: Computational rhythm description

International Conference on Music Information Retrieval, 2006

Rhythm representation

Rhythm

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o Rhythm refers to the periodic and hierarchic framework

that embeds the timing of events (onsets) within the audio

signal.

o Rhythm detection involves detecting events at each

metrical level.•Tatum

•Tactus

•Measure

o Onsets are detected via abrupt increases in loudness, or

equivalently, abrupt energy changes within frequency bands.

Rhythm is represented by the detected periodicities of the

sequence of onsets.

Department of Electrical

Engineering , IIT Bombay

Note onset detection

• Transcription

FRSM 2012 - 18-19 January, 2012, KIIT

College of Engineering, Gurgaon18