Use the free Polyrhythm Metronome below: your data never leaves your browser — all work happens on your device, and nothing is uploaded to any server.
Two rhythms at once: what a polyrhythm is
Most music has one rhythm at a time. A polyrhythm has two, played simultaneously, in the same span of time. The classic example is 3 against 2: one hand plays three even beats while the other plays two even beats, both fitting into the same bar. Neither hand is playing “wrong” — they are simply dividing the same time differently. The result sounds rich and slightly tense, because the beats line up only at the start of each cycle and then drift apart until they meet again. That tension and resolution is why polyrhythms appear in music from West Africa to jazz to progressive rock: they make a simple bar feel layered and alive.
This polyrhythm metronome lets you hear that layering directly. Choose a ratio, press start, and two click sounds play together: high clicks for the first rhythm, low clicks for the second. In 3 against 2, you hear three high clicks and two low clicks per cycle, with the first click of each group landing together. In 4 against 5, you hear four high clicks and five low clicks per cycle, a denser pattern that takes a few cycles to feel. The tool schedules both streams with the Tone.js audio library, so the timing is sample-accurate rather than approximate, which matters for rhythms: a polyrhythm played with sloppy timing just sounds like mistakes.
The maths behind the patterns
Every polyrhythm in this tool is built from one simple idea: the least common multiple. To play 3 against 2, you need a grid fine enough that both rhythms land exactly on grid points. The least common multiple of 3 and 2 is 6, so the cycle is divided into 6 equal steps: the first rhythm clicks on steps 0, 2, and 4, and the second clicks on steps 0 and 3. Step 0 is shared, which is why the cycle starts together. For 4 against 5, the least common multiple is 20, so the cycle has 20 steps: the first rhythm clicks every 5 steps, the second every 4 steps, and again they share only step 0.
That arithmetic explains why some polyrhythms feel harder than others: the more steps in the cycle, the harder it is to hold both patterns in mind. 2 against 3, with 6 steps, is learnable in minutes. 4 against 5, with 20 steps, takes real practice. And the shared first beat is the anchor: if you lose your place, wait for it and start counting again.
How to practise with it
Start with 2 against 3, the gentlest polyrhythm in the set, at a slow cycle tempo of about 60 to 90 BPM. Listen for a full cycle first, without playing anything: notice the shared beat, then the pattern of high and low clicks between anchors. Then tap along with one rhythm only — say, the high clicks — while listening to the other. When that feels steady, switch: tap the low clicks while listening to the high ones. Only then try to play both, for example by tapping one rhythm with each hand, or by clapping one and tapping a foot for the other.
The combined clicks in 3 against 2 fall on steps 0, 2, 3, and 4 of the 6-step grid, and musicians often count it as “one – and – a – two – and” or use the phrase “not difficult” spoken evenly. For 3 against 4, the combined pattern is denser, and counting the full grid out loud — one through twelve, accenting the clicks — works better than a phrase. Slow the tempo down before you speed it up: a polyrhythm played cleanly at 60 BPM teaches more than the same pattern fumbled at 140.
The five ratios in this tool
2 against 3 is the starting point, common in folk, jazz, and classical music, and the most useful polyrhythm to learn first. 3 against 4 is a step up: it appears in jazz and in much African music, and it feels like a gentle tug between two groupings. 4 against 5 is advanced: five is an unusual grouping for most Western ears, and holding four against it requires counting the grid, not just feeling it. 3 against 5 is similarly advanced, with a 15-step cycle. 2 against 5 is the most asymmetric ratio here: two slow beats against five fast ones, which sounds almost like a melody over a drone. Try them in that order, .
Who needs polyrhythms
Drummers meet polyrhythms constantly, because the drum kit is built for them: different limbs play different patterns by design. Pianists meet them when the left hand plays triplets against right-hand straight beats, or the reverse. Guitarists meet them in fingerstyle playing, where the thumb keeps one rhythm and the fingers play another. Singers meet them in complex vocal lines over a steady groove. And composers use them deliberately, because a polyrhythm adds rhythmic interest without changing the harmony or the melody at all: the same notes, regrouped in time, sound like a different piece.
Even if you never play an instrument, listening to polyrhythms trains your ear for rhythmic complexity. Once you can hear 3 against 2, you will start noticing it in songs you thought were simple. This tool needs no account and no download, and it keeps nothing.