There's a lot of talk about ear training for EQ and almost none about training for time. Yet it's half the job: a production with perfect frequencies and stiff groove sounds like a demo, while a mediocre mix with good feel holds up on its own.
The problem is that rhythm is almost never practised with measurement. You play along to the song and assume it's fine. Here the accuracy window is objective: you know in milliseconds whether you were early or late, and that immediate feedback is what sharpens perception in weeks instead of years.
The catalogue is 37 songs across four levels, and 8 of them are by real independent artists from the Artist Pool — Maia San Miguel, Oh Margó, Monár, Gillian Harwin, NVVP — rather than generated or pulled from a loop library. That isn't a marketing detail: playing over a song with a human drummer behind it teaches things a perfect click can't, starting with the fact that a real recording's pulse breathes.
One note that carries over to mixing: after hours with a song you stop hearing its pulse, because you know it by heart and your head fills it in even when the audio isn't. It's the same phenomenon that stops you noticing you have too much low end. A short rhythmic exercise on unfamiliar material resets that reference, which is why it pays off more as a warm-up before a session than as a diversion afterwards.
Right now 32 of the 37 in the catalogue, with no account, in the browser. This page counts that figure from the catalogue itself, so if the split changes it updates on its own.
It's most useful if you aren't. A sense of tempo decides when an element enters, how a loop gets quantised, and whether an automation move lands where it should. It's a production skill, not an instrumental one.
The game measures against the audio, not the system clock, but wired headphones remove the biggest variable. Bluetooth adds tens of milliseconds and makes the measurement meaningless.
Yes, with three touch buttons instead of the keyboard. The precision asked for is the same; what changes is the gesture.
Rhythmic hearing is one skill on the full map, which lives in the ear training guide. When the groove is there and what fails is where each hit sits, the sidechain guide and the one on kick and bass come in. To work tempo and key on your own files, the BPM and key detector.