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CSC475 Music Information Retrieval
Symbolic Music Representations
George Tzanetakis
University of Victoria
2014
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Table of Contents I
1 Western Common Music Notation
2 Digital Formats for Symbolic Representations
3 Tools for Symbolic Representations
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Introduction
Music notation and theory are complex topics that can
take many years to master
This presentation barely scratches the surface of the
subject
The main goal is to provide enough background for
students with no formal music training to be able to read
and understand MIR papers that use terminology from
music notation and theory
It is never too late to get some formal music training
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History of Music Notation
Earliest known form of music notation in cuneiform
Sumerian tablet around 2000 BC.
Initially a mnemonic aid to oral instruction, performance
and transmission it evolved into a codified set of
conventions that transformed how music was created,
distributed and consumed across time and space.
Notation can be viewed as a visual representation of
instructions for how to perform an instrument. Tablature
notation for example is specific to stringed instruments.
Primary focus of traditional musicology
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Western Common Music Notation
Originally used in
European Classical Music
is currently used in many
genres around the world
Mainly encodes pitch and
timing (to a certain
degree designed for
keyboard instruments)
Considerable freedom in
interpretation
Five staff lines
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Notating rhythm
Symbols indicate relative durations in terms of multiples
(or fractions) of underlying regular pulse
If tempo is specified then exact durations can be
computed (for example the first symbol would last 60
seconds / 85 BPM = 0.706 seconds)
A different set of symbols is used to indicate rests
Numbers under symbols indicate the duration in terms of
eighth notes. Each measure is subdivded into 2 half
notes, 4 quarter notes, 8 eighth notes.
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Time signature and measures
Measure (or bar) lines indicate regular groupings of notes
Time signature shows the rhythmic content of each
measure
Compound rhythms consists of smaller rhythmic units
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Notating pitches
Clef sign anchors the five staff lines to a particular pitch
Note symbols are either placed on staff lines or between
staff lines.
Successive note symbols (one between lines followed by
one on a staff line or the other way around) correspond to
successive white notes on a keyboard.
Invisible staff lines extend above and below
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Notating pitches
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Repeat signs and structure
Repeat signs and other notation conventions can be
thought of as a “proto” programming language providing
looping constructs and goto statements
Hierarchical structure is common i.e ABAA form
Structure = segmentation + similarity
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Structure of Naima by J. Coltrane
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Intervals
Intervals are pairs of pitches
Melodic when the pitches are played in succession
Harmonic when the pitches are played simultaneously
Uniquely characterized by number of semitones (although
typically named using a more complex system)
(microtuning also possible)
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Naming of intervals
The most common naming convention for intervals uses two
attributes to describe them: quality and number.
Quality
Quality: perfect, major, minor, augmented, diminished.
Number
Number: unison, second, third, fifth, sixth, seventh, octave
and is based on counting staff positions
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Scales and Modes
A scale is a sequence of intervals typically consisting of whole
tones and semitones and spanning an octave. Diatonic scales
are the ones that can be played using only the white keys on a
piano. They are called modes and have ancient greek names.
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Major/Minor Scales
The scales used in composed Western classical music are
primarily the major and minor scales. The harmonic minor
scale has an augmented second (A) that occurs between the
6th and 7th tone.
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Enharmonic Spelling
The naming of intervals (and absolute pitches) is not unique
meaning that the same exact note can have two different
names as in C # and Db. Similarly the same interval can be a
minor third or an augmented second. The spelling comes from
the role an interval plays as part of a scale as well as the
historical tuning practice of having different frequency ratios
for enharmonic intervals.
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Chords
A chord is a set of two or more notes that sound
simultaneously. A chord label can also be applied to a music
excerpt (typically a measure) by inferring, using various rules
of harmony, what theoretical chord would sound “good” with
the underlying music material. The basis of the western
classical and pop music chord system is the triad consisting of
three notes. Different naming schemes are used for chords.
Jazz and Pop music frequently use naming based on triad with
additional modifiers for the non-triad notes.
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Root, Inversions, Voicings
The lowest note of a chord in its “default” position is called
the root. Inversions occur when the lowest note of a chord is
different than the root. Voicings are different arrangements
of the chord notes that can include repeated notes as well as
octaves.
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Chord Progressions and Harmony
Sequences of chords are called chord progressions. Certain
progressions are more common than others and also indicate
the key of a piece. Frequently chords are constructed from
subsets of notes from a particular scale. The root of the scale
is called the tonic and defines the key of the piece. For
example a piece in C Major will mostly consist of chords
formed by the notes of the C major scale. Modulation refers
to a change in key. Chords have specific qualities and
functions which are studied in Harmonic analysis.
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Jazz Lead Sheets
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TuneDex
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Pianoroll
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Table of Contents I
1 Western Common Music Notation
2 Digital Formats for Symbolic Representations
3 Tools for Symbolic Representations
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MIDI
Musical Instrument Digital Interface
MIDI is both a communication protocol (and associated file
format) as well as a hardware connector specification that
allows the exchange of information between electronic musical
instruments and computers. It was developed in the early 80s
and was mostly designed with keyboard instruments in mind.
Essentially piano-roll representation of music.
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Lilypond
Music engraving program
Text language for input that is complied
Encodes much more than just notes and duration in order
to produce a visual musical score
Produces beautiful looking scores and is free
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Music XML
Extensible Markup
Language (XML) format
for interchanging
information about scores
Supported by more than a
170 notation, score
writing applications
Proprietary but open
specification
Hard to read but
comprehensive
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Table of Contents I
1 Western Common Music Notation
2 Digital Formats for Symbolic Representations
3 Tools for Symbolic Representations
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jSymbolic - jMIR
Software in Java for extracting
high level musical features from
symbolic music representations,
specifically MIDI files
Features capture aspects of
instrumentation, texture,
rhythm, dynamics, pitch
statistics, melody, and chords
Part of jMIR a more general
package for MIR including audio,
lyrics, web feature extraction as
well as a classification engine
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music21
Set of tools written in Python for computer aided
musicology
Corpora included is a great feature
Works with MusicXML, MIDI
Example: add german name (i.e., B=B, B=H, A= Ais)
under each note of a Bach chorale
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music 21 pitch/duration distribution
Distribution of pitches and note duration for a Chopin
Mazurka using music21.
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