A Dart package for transposing chords into any given key.
- Transpose chords from one key to another
- Transpose chords up or down semitones
- Find chords in lyrics and transpose them into another key
- Find chords in lyrics and transpose up or down semitones
First initialize the ChordTransposer:
final transposer = ChordTransposer();Transpose a single chord from one key to another:
transposer.chordToKey(chord: 'D/F#', fromKey: 'A', toKey: 'G'); // => C/ETranspose multiple chords from one key to another. If fromKey is not given, it will use the first chord in the list:
transposer.chordsToKey(chords: ['C', 'F', 'Am', 'G7', 'Bdim'], toKey: 'E'); // => [E, A, C#m, B7, D#dim]Transpose a single chord up or down semitones:
transposer.chordUp(chord: 'D', semitones: 5); // => G
transposer.chordDown(chord: 'Bb', semitones: 2); // => AbTranspose multiple chords up or down semitones:
transposer.chordsUp(chords: ['D','Aadd9'], semitones: 4); // => [Gb, Dbadd9]
transposer.chordsDown(chords: ['Bb7/D', 'Eb'], semitones: 6); // => [E7/G#, A]final lyrics = '''
[C]Twinkle, twinkle [F]little [C]star.
[F]How I [C]wonder [G7]what you [C]are.
''';Tranpose lyrics from one key to another. If fromKey is not given, it will use the first chord in the lyrics. When ignoreInvalids is set to true (default), it will ignore all invalid chords. When it is set to false, it will throw an error if there is an invalid chord:
transposer.lyricsToKey(lyrics: lyrics, fromKey: 'C', toKey: 'G'); // =>
// [G]Twinkle, twinkle [C]little [G]star.
// [C]How I [G]wonder [D7]what you [G]are.Transpose lyrics up or down semitones:
transposer.lyricsUp(lyrics: lyrics, semitones: 5); // =>
// [F]Twinkle, twinkle [A]little [F]star.
// [Bb]How I [F]wonder [C7]what you [F]are.
transposer.lyricsDown(lyrics: lyrics, semitones: 3); // =>
// [A]Twinkle, twinkle [D]little [A]star.
// [D]How I [A]wonder [E7]what you [A]are.This package built to work with paurakhsharma's flutter_chord package and was inpsired by ddycai's chord-transposer npm package.