PolyPulse Drum Trainer
Odd Subdivisions, Side by Side
A step sequencer where every lane keeps its own subdivision. Put quintuplets against straight sixteenths, or 7-over-4 against a triplet, and hear how they fall. Click a step once for a note, twice for an accent, three times to clear it.
16 steps · 4:1 per beat · 150.0 ms
16 steps · 4:1 per beat · 150.0 ms
20 steps · 5:1 per beat · 120.0 ms
7 steps · 7:4 per beat · 342.9 ms
12 steps · 3:1 per beat · 200.0 ms
16 steps · 4:1 per beat · 150.0 ms
How to read it
Every lane spans the same number of beats, so a five-per-beat lane and a four-per-beat lane are drawn the same width. The misalignment against the beat ticks along the top is the thing you're listening for.
Subdivisions
Each lane is set as n notes per d beats. 4:1 is sixteenths, 3:1 is eighth-note triplets, 5:1 is sixteenth quintuplets, 7:1 septuplets. Ratios like 5:2 or 7:4 spread an odd number of notes across several beats, so they only resolve every few bars.
Polymeter
Lane length is set in beats and can differ per lane. A three-beat lane against a four-beat lane realigns every twelve beats — a different kind of odd from the subdivisions above, and they stack.
Sound
Everything is synthesised in the browser with Web Audio — no samples, nothing to load. Each lane has its own level fader; the master is in the bar at the top.