CSC475 Music Information Retrieval - Symbolic Music ...marsyas.cs.uvic.ca/mirBook/csc475_symbolic.pdfHistory of Music Notation Earliest known form of music notation in cuneiform Sumerian

CSC475 Music Information RetrievalSymbolic Music Representations

George Tzanetakis

University of Victoria

2014

G. Tzanetakis 1 / 30

Table of Contents I

1 Western Common Music Notation

2 Digital Formats for Symbolic Representations

3 Tools for Symbolic Representations


Introduction

Music notation and theory are complex topics that cantake many years to master

This presentation barely scratches the surface of thesubject

The main goal is to provide enough background forstudents with no formal music training to be able to readand understand MIR papers that use terminology frommusic notation and theory

It is never too late to get some formal music training


History of Music Notation

Earliest known form of music notation in cuneiformSumerian tablet around 2000 BC.

Initially a mnemonic aid to oral instruction, performanceand transmission it evolved into a codified set ofconventions that transformed how music was created,distributed and consumed across time and space.

Notation can be viewed as a visual representation ofinstructions for how to perform an instrument. Tablaturenotation for example is specific to stringed instruments.

Primary focus of traditional musicology


Western Common Music Notation

Originally used inEuropean Classical Musicis currently used in manygenres around the world

Mainly encodes pitch andtiming (to a certaindegree designed forkeyboard instruments)

Considerable freedom ininterpretation

Five staff lines


Notating rhythm

Symbols indicate relative durations in terms of multiples(or fractions) of underlying regular pulse

If tempo is specified then exact durations can becomputed (for example the first symbol would last 60seconds / 85 BPM = 0.706 seconds)

A different set of symbols is used to indicate rests

Numbers under symbols indicate the duration in terms ofeighth notes. Each measure is subdivded into 2 halfnotes, 4 quarter notes, 8 eighth notes.


Time signature and measures

Measure (or bar) lines indicate regular groupings of notes

Time signature shows the rhythmic content of eachmeasure

Compound rhythms consists of smaller rhythmic units


Notating pitches

Clef sign anchors the five staff lines to a particular pitch

Note symbols are either placed on staff lines or betweenstaff lines.

Successive note symbols (one between lines followed byone on a staff line or the other way around) correspond tosuccessive white notes on a keyboard.

Invisible staff lines extend above and below


Notating pitches


Repeat signs and structure

Repeat signs and other notation conventions can bethought of as a “proto” programming language providinglooping constructs and goto statements

Hierarchical structure is common i.e ABAA form

Structure = segmentation + similarity


Structure of Naima by J. Coltrane


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 (althoughtypically named using a more complex system)(microtuning also possible)


Naming of intervals

The most common naming convention for intervals uses twoattributes to describe them: quality and number.

Quality

Quality: perfect, major, minor, augmented, diminished.

Number

Number: unison, second, third, fifth, sixth, seventh, octaveand is based on counting staff positions


Scales and Modes

A scale is a sequence of intervals typically consisting of wholetones and semitones and spanning an octave. Diatonic scalesare the ones that can be played using only the white keys on apiano. They are called modes and have ancient greek names.


Major/Minor Scales

The scales used in composed Western classical music areprimarily the major and minor scales. The harmonic minorscale has an augmented second (A) that occurs between the6th and 7th tone.


Enharmonic Spelling

The naming of intervals (and absolute pitches) is not uniquemeaning that the same exact note can have two differentnames as in C# and Db. Similarly the same interval can be aminor third or an augmented second. The spelling comes fromthe role an interval plays as part of a scale as well as thehistorical tuning practice of having different frequency ratiosfor enharmonic intervals.


Chords

A chord is a set of two or more notes that soundsimultaneously. A chord label can also be applied to a musicexcerpt (typically a measure) by inferring, using various rulesof harmony, what theoretical chord would sound “good” withthe underlying music material. The basis of the westernclassical and pop music chord system is the triad consisting ofthree notes. Different naming schemes are used for chords.Jazz and Pop music frequently use naming based on triad withadditional modifiers for the non-triad notes.


Root, Inversions, Voicings

The lowest note of a chord in its “default” position is calledthe root. Inversions occur when the lowest note of a chord isdifferent than the root. Voicings are different arrangementsof the chord notes that can include repeated notes as well asoctaves.


Chord Progressions and Harmony

Sequences of chords are called chord progressions. Certainprogressions are more common than others and also indicatethe key of a piece. Frequently chords are constructed fromsubsets of notes from a particular scale. The root of the scaleis called the tonic and defines the key of the piece. Forexample a piece in C Major will mostly consist of chordsformed by the notes of the C major scale. Modulation refersto a change in key. Chords have specific qualities andfunctions which are studied in Harmonic analysis.


Jazz Lead Sheets


TuneDex


Pianoroll


Table of Contents I





MIDI

Musical Instrument Digital Interface

MIDI is both a communication protocol (and associated fileformat) as well as a hardware connector specification thatallows the exchange of information between electronic musicalinstruments and computers. It was developed in the early 80sand was mostly designed with keyboard instruments in mind.Essentially piano-roll representation of music.


Lilypond

Music engraving program

Text language for input that is complied

Encodes much more than just notes and duration in orderto produce a visual musical score

Produces beautiful looking scores and is free


Music XML

Extensible MarkupLanguage (XML) formatfor interchanginginformation about scores

Supported by more than a170 notation, scorewriting applications

Proprietary but openspecification

Hard to read butcomprehensive


Table of Contents I





jSymbolic - jMIR

Software in Java for extractinghigh level musical features fromsymbolic music representations,specifically MIDI files

Features capture aspects ofinstrumentation, texture,rhythm, dynamics, pitchstatistics, melody, and chords

Part of jMIR a more generalpackage for MIR including audio,lyrics, web feature extraction aswell as a classification engine


music21

Set of tools written in Python for computer aidedmusicology

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


music 21 pitch/duration distribution

Distribution of pitches and note duration for a ChopinMazurka using music21.


Documents

CSC475 Music Information Retrieval - Symbolic Music ...marsyas.cs.uvic.ca/mirBook/csc475_symbolic.pdfHistory of Music Notation Earliest known form of music notation in cuneiform Sumerian