analysis / Symbolic
Key sequence
A time-ordered map of keys and modulations. It keeps track of where a piece changes tonal center instead of assigning one key to the whole piece.
Try it
Map key changes across a piece
Choose a key at each beat boundary to create a modulation map. Editing one segment changes that local key; transposing the whole sequence moves every tonic while preserving modes and boundary times.
Modulation timeline · beats 0–24
Original key map
0:C major,8:G major,16:A minorTransposed key map
0:C major,8:G major,16:A minorSelected key
C majorSelected scale PCs
0-2-4-5-7-9-11The clock shows the selected key’s scale pitch classes. Changing key within the map is a modulation; the semitone control moves every segment together.
Written forms
Ways to write this concept
Each notation describes the same underlying object. Load a playable example to hear one MIDI realization in the Code Sequencer.
keys
Ordered modulation map: comma-separated 'startBeat:key' entries
0:C major, 8:A minor, 16:C major