Create an empty PhiraExtra structure.
PhiraExtra
Optional
Optional initial BPM value (creates a single BPM entry at beat 0 in extra.bpm; only needed when the extra has its own independent BPM list).
extra.bpm
A minimal valid PhiraExtra with an empty effects array.
const extra = createExtra(); // no BPMconst extra2 = createExtra(140); // with BPM entry at beat 0 Copy
const extra = createExtra(); // no BPMconst extra2 = createExtra(140); // with BPM entry at beat 0
Create an empty
PhiraExtrastructure.