Metronome

What a metronome is for. It plays a click at a fixed rate so you have something outside your own playing to line up against. That is harder than it sounds: almost everyone rushes the easy bars and drags the hard ones, and you cannot hear yourself doing it, because the reference you are checking against is the same internal clock that is drifting. A metronome replaces that reference with one that does not care how difficult the passage is. Set the tempo, count yourself in, and the moment your note and the click stop landing together you have found something to practise.

Tempo, and what the Italian words mean. BPM is beats per minute — at 60 BPM a beat lasts exactly one second, at 120 it lasts half a second, and at 180 it lasts a third of one. This tool covers 20 to 300 BPM, which spans everything from a funeral march to double-time bebop. The traditional markings printed on scores are ranges rather than numbers: Largo is broadly 40–60, Adagio 66–76, Andante 76–108 (a walking pace), Moderato 108–120, Allegro 120–140, Vivace 140–168, and Presto 168–200. Sources disagree by a few BPM either way, so treat the marking shown under the tempo as a label rather than a measurement — the number is the thing you and anyone else can agree on.

The downbeat is the point of the time signature. A stream of identical clicks tells you the tempo and nothing else; you still have to count the bar yourself, and if you lose your place there is nothing to find it with. Choosing a meter here gives beat 1 a higher, louder click, so the bar has an audible edge. In 4/4 you get one strong click and three plain ones. In 3/4 the strong click comes round every three, which is why the waltz feels different from a march even at the same tempo.

Odd and compound meters get a middle accent too. 7/8 is not seven equal beats — it is almost always counted in groups, and this metronome counts it 2 + 2 + 3, putting a medium click on beats 3 and 5 between the strong one on beat 1. 5/4 is grouped 3 + 2, and 6/8, 9/8 and 12/8 are grouped in threes, so 6/8 gets its medium click on beat 4. That grouping is what makes an odd meter playable rather than a counting exercise, and it is the difference between a 7/8 click track and seven clicks in a row.

What the BPM counts in 6/8 and 7/8. Here the tempo always counts the note value in the lower number of the time signature: 120 BPM in 4/4 is 120 quarter notes a minute, and 120 BPM in 6/8 is 120 eighth notes a minute — so a 6/8 bar at 120 lasts three seconds, while a 4/4 bar at 120 lasts two. Players who count 6/8 in two ("dotted-quarter equals 40") should set the tempo to three times that number and listen for the strong and medium clicks as their two beats. This is worth knowing because printed metronome marks are usually written against a note value, and the two conventions differ by exactly a factor of three in compound time.

Subdivisions are for the gaps between the beats. Rushing rarely happens on the beat — it happens in the space after it, where there is nothing to check against. Turning on eighths, triplets or sixteenths fills that space with a quieter, higher tick, so a run of fast notes has something to sit on. Two useful habits: practise a dotted or swung rhythm with triplets on, and once a passage is solid, switch the subdivision off, because a click you are leaning on is a click you have not yet learned to do without.

Tap tempo, for a tempo you can only hear. Tap the button — or press T — four or more times in time with whatever you are trying to match, and the tempo follows. It averages up to eight intervals rather than taking the last one, because a hand is several milliseconds out on every tap and one interval passes all of that straight into the number. Leave it 3 seconds and the next tap starts a fresh count, so an abandoned attempt never contaminates the next.

How to actually use it. The standard method for a passage you cannot play is to find the fastest tempo at which you can play it cleanly — usually much slower than you expect — and then raise it by about 5 BPM at a time, dropping back the moment it stops being clean. Slow practice is what most players skip and what most teachers ask for first. For timing rather than speed, try setting the click on beats 2 and 4 only (halve the tempo in 4/4 and treat each click as beat 2, then 4), which removes the downbeat crutch and exposes exactly how much you were relying on it.

How it works, and what it does not do. Every click is synthesised in your browser with the Web Audio API — a short pitched tone and a filtered noise transient — so there is no audio file to download and the tool works with the network switched off. Clicks are scheduled ahead of time against the audio hardware's own clock rather than fired by a timer, which is what keeps the beat steady while the page is doing something else. Nothing is uploaded, there are no accounts, and there is no analytics or tracking of any kind: the tempo, meter and volume are stored in this browser, and the link in the address bar is the only thing that leaves the page — and only if you send it to someone.