Musician Code

Question 1

What’s the basic strategy in getting accurate timing in JavaScript/NextJs?

Answer 1

Uses Web Audio API’s scheduling system
It uses a function that allows you to store (in seconds) exactly when you want something to play

Question 2

What do you read when you see ‘SCHEDULE_DEADLINE’

    while (NEXT_NOTE_TIME() < SCHEDULE_DEADLINE()) {
        scheduleNote(currentBeat, NEXT_NOTE_TIME());
        nextNote();
    }

Answer 2

The next 25 milliseconds

Question 3

Explain nextNote()

const scheduler = useCallback(() => {
    const audioContext = audioContextRef.current;
    if (!audioContext) return;

    while (NEXT_NOTE_TIME() < SCHEDULE_DEADLINE()) {
        scheduleNote(currentBeat, NEXT_NOTE_TIME());
        nextNote();
    }

    timerIdRef.current = setTimeout(scheduler, lookAhead);
}, [currentBeat]);

Answer 3

Question 4

Please explain the code of the flow

Answer 4

Question 5

Using the code logic.. Doesn’t it mean that the first note will always be skipped since the time we get to scheduleNote(), the time has already passed for NEXT_NOTE_TIME().. How come it’s still playing?

Answer 5

Question 6

What is % (Modulo)?

Answer 6

Question 7

Explain this line of code

timerIdRef.current = setTimeout(scheduler, lookAhead);

Answer 7