tonal-pcset

pcset

tonal-pcset is a collection of functions to work with pitch class sets, oriented to make comparations (isEqual, isSubset, isSuperset)

This is part of tonal music theory library.

You can install via npm: npm i --save tonal-pcset

var pcset = require('tonal-pcset')
pcset.isEqual('c2 d5 e6', 'c6 e3 d1') // => true

API documentation

• pcset
  • .chroma(set) ⇒ String
  • .notes(notes) ⇒ Array
  • .modes(set, normalize) ⇒ Array.<String>
  • .chromaModes()
  • .isChroma(chroma) ⇒ Boolean
  • .intervals(pcset) ⇒ Array
  • .fromChroma(binary, tonic) ⇒ Array
  • .isEqual(set1, set2) ⇒ Boolean
  • .isSubset(set, test) ⇒ Boolean
  • .isSuperset(set, test) ⇒ Boolean
  • .includes(set, note) ⇒ Boolean
  • .filter(set, notes) ⇒ Array

pcset.chroma(set) ⇒ String

Get chroma of a pitch class set. A chroma identifies each set uniquely. It's a 12-digit binary each presenting one semitone of the octave.

Note that this function accepts a chroma as parameter and return it without modification.

Kind: static method of pcset
Returns: String - a binary representation of the pitch class set

Param	Type	Description
set	Array | String	the pitch class set

Example

pcset.chroma('C D E') // => '1010100000000'

pcset.notes(notes) ⇒ Array

Deprecated

Kind: static method of pcset
Returns: Array - an array of pitch class sets
See: collection.pcset Given a list of notes, return the pitch class names of the set starting with the first note of the list

Param	Type	Description
notes	String | Array	the pitch class set notes

pcset.modes(set, normalize) ⇒ Array.<String>

Given a a list of notes or a pcset chroma, produce the rotations of the chroma discarding the ones that starts with '0'

This is used, for example, to get all the modes of a scale.

Kind: static method of pcset
Returns: Array.<String> - an array with all the modes of the chroma

Param	Type	Description
set	Array | String	the list of notes or pitchChr of the set
normalize	Boolean	(Optional, true by default) remove all the rotations that starts with '0'

Example

pcset.modes('C E G')

pcset.chromaModes()

Deprecated

Kind: static method of pcset
See: modes

pcset.isChroma(chroma) ⇒ Boolean

Test if the given string is a pitch class set chroma.

Kind: static method of pcset
Returns: Boolean - true if its a valid pcset chroma

Param	Type	Description
chroma	String	the pitch class set chroma

Example

pcset.isChroma('101010101010') // => true
pcset.isChroma('101001') // => false

pcset.intervals(pcset) ⇒ Array

Given a pcset (notes or chroma) return it's intervals

Kind: static method of pcset
Returns: Array - intervals or empty array if not valid pcset

Param	Type	Description
pcset	String | Array	the pitch class set (notes or chroma)

Example

pcset.intervals('1010100000000') => ['C', 'D', 'E']

pcset.fromChroma(binary, tonic) ⇒ Array

Deprecated

Kind: static method of pcset
Returns: Array - a list of notes or intervals
See: intervals Given a pitch class set in binary notation it returns the intervals or notes (depending on the tonic)

Param	Type	Description
binary	String	the pitch class set in binary representation
tonic	String | Pitch	the pitch class set tonic

Example

pcset.fromChroma('101010101010', 'C') // => ['C', 'D', 'E', 'Gb', 'Ab', 'Bb']

pcset.isEqual(set1, set2) ⇒ Boolean

Test if two pitch class sets are identical

Kind: static method of pcset
Returns: Boolean - true if they are equal

Param	Type	Description
set1	Array | String	one of the pitch class sets
set2	Array | String	the other pitch class set

Example

pcset.isEqual('c2 d3', 'c5 d2') // => true

pcset.isSubset(set, test) ⇒ Boolean

Test if a pitch class set is a subset of another

Kind: static method of pcset
Returns: Boolean - true if the test set is a subset of the set

Param	Type	Description
set	Array | String	the base set to test against
test	Array | String	the set to test

Example

pcset.subset('c d e', 'C2 D4 D5 C6') // => true

pcset.isSuperset(set, test) ⇒ Boolean

Test if a pitch class set is a superset

Kind: static method of pcset
Returns: Boolean - true if the test set is a superset of the set

Param	Type	Description
set	Array | String	the base set to test against
test	Array | String	the set to test

Example

pcset.isSuperset('c d e', 'C2 D4 F4 D5 E5 C6') // => true

pcset.includes(set, note) ⇒ Boolean

Test if a given pitch class set includes a note

Kind: static method of pcset
Returns: Boolean - true if the note is included in the pcset

Param	Type	Description
set	Array | String	the base set to test against
note	String | Pitch	the note to test

Example

pcset.includes('c d e', 'C4') // =A true
pcset.includes('c d e', 'C#4') // =A false

pcset.filter(set, notes) ⇒ Array

Filter a list with a pitch class set

Kind: static method of pcset
Returns: Array - the filtered notes

Param	Type	Description
set	Array | String	the pitch class set notes
notes	Array | String	the note list to be filtered

Example

pcset.filter('c d e', 'c2 c#2 d2 c3 c#3 d3') // => [ 'c2', 'd2', 'c3', 'd3' ])
pcset.filter('c2', 'c2 c#2 d2 c3 c#3 d3') // => [ 'c2', 'c3' ])