One beat, reshaped like a melody
A groove is a grid — one row per drum, one column per sixteenth of the bar. Each cell is a hit or a rest, nothing more:
1 . . . 2 . . . 3 . . . 4 . . .
kick x . . . . . . x . . x . . . . .
snare . . . . x . . . . . . . x . . .
hat 3 . 1 . 3 . 1 . 3 . 1 . 3 . 1 .That’s the beat as written: a syncopated kick, a snare on the backbeat (2 and 4), a steady eighth-note hat. The raw material.
Because the beat is just a grid of numbers, the same moves that reshape a melody reshape it too — and each reshaped beat points back at this one, so editing the source re-derives everything below it:
- Reversed — flip the grid end to end. Every hit mirrors at once and the snare slides off the backbeat.
- Rotated a beat — turn the bar one beat later. The snare that fell on 2 and 4 lands on 1 and 3; the hat pulse holds.
It’s the exact move you’d use to play a melody backward, or to start a phrase later in the bar — the same handful of transforms that flip a song’s sections or a stack of voices. The difference is only what they point at: here the “notes” being reversed and rotated are the hits of a drum beat, so what changes is the groove itself.