A tempo change: the beat it takes effect on, and the tempo it sets.
The tempo holds until the next entry, so a map of one entry is a constant tempo for the whole timeline.
Readonly
Onset in quarter-note beats, absolute from the start of the timeline.
Quarter-note beats per minute from startBeat onwards.
startBeat
A tempo change: the beat it takes effect on, and the tempo it sets.
The tempo holds until the next entry, so a map of one entry is a constant tempo for the whole timeline.