Practice log and metronome

How it works

Pick what you're practising and start the metronome: the practice timer starts with it, and when you stop, the session goes into today's log with its minutes. Nothing to write down.

While the click runs, any tempo you hold for half a minute counts as played (our rule of thumb: long enough to get through a passage once). Each practice day, a piece's fastest held tempo becomes a step on its staircase, climbing toward the goal you set, usually the marking on the score. Teachers' advice is to start slow and raise the click a few beats per minute only once it's clean; the staircase shows whether that's happening.

The click is timed by your device's audio clock, not the page: every click is placed a tenth of a second ahead, the method from Chris Wilson's "A Tale of Two Clocks", so a busy page can't push it off the beat. On an iPhone it plays even with the silent switch on, unless you choose to let other apps keep playing.

Minutes add up per day and week for a practice record. They aren't the whole story: in one study of pianists, how long they practised didn't predict how well they played the next day, but how they practised did. Everything stays on this device.

Questions people ask

How do I use a metronome to get a piece up to tempo?

Start well below the marking, at a tempo where you can play it cleanly, and raise the click only once it's accurate, a few beats per minute at a time. That's teachers' advice rather than research: Eastman's community music school suggests starting a piece marked 120 at 60, and Musicnotes suggests raising it 2 to 4 bpm at a time.

How long should I practise each day?

There's no number that works for everyone, and how you practise matters more than how long. In Duke, Simmons and Cash's 2009 study, pianists' practice time and number of run-throughs didn't predict how well they played a passage the next day; their strategies did, such as slowing down to get tricky spots right.

How do I set a metronome for 6/8?

Count it in two: the beat is a dotted quarter, split into three eighths. Choose 6/8 here and the tempo counts dotted quarters, with softer clicks on the eighths in between. Open Music Theory describes compound meters as dividing the beat into three, with a dotted beat.

Why log practice with a timer instead of from memory?

Because memory runs high: violinists in Ericsson, Krampe and Tesch-Römer's 1993 study estimated a week's practice 5.2 hours higher than their own diaries showed. A timer that starts with the metronome writes the real minutes down.

How accurate is this metronome?

Its clicks are timed by your device's audio clock, not by the web page: each one is placed a tenth of a second ahead, the method in Chris Wilson's "A Tale of Two Clocks", so a busy page doesn't push them around. A tempo change lands on the next click.

Sources

1. Chris Wilson: A Tale of Two Clocks, scheduling Web Audio with precision (web.dev)
2. Chris Wilson: metronome demo source (lookahead, Web Worker timer)
3. Chrome: heavy throttling of chained JS timers (Chrome 88)
4. MDN: Page Visibility API (audible tabs aren't throttled)
5. MDN: AudioScheduledSourceNode.start()
6. W3C Audio Session (playback and ambient types)
7. WebKit bug 237322: Web Audio muted by the iOS ringer switch
8. WCAG 2.2: three flashes or below threshold
9. Wittner: Maelzel metronome instructions (tempo scale 40–208)
10. Open Music Theory: meter (simple and compound)
11. Duke, Simmons and Cash 2009: It's not how much; it's how
12. Ericsson, Krampe and Tesch-Römer 1993: deliberate practice (practice diaries)
13. Eastman Community Music School: the metronome, getting started
14. Musicnotes: how to practice with a metronome