Click steps on the grid to place hits, press Play loop to hear the bar repeat, and keep editing while it plays. Each change joins the loop at the same point in the bar, so the groove never restarts.
The grid
Sixteen steps make one bar of sixteenth notes in 4/4. The darker squares start each beat. A row is one drum, and each drum plays one hit at a time: a new hit fades the previous one out over 3 ms rather than letting two of the same drum overlap.
A pattern is saved in the page address, grid, tempo, levels, and all. Copy the URL to keep a beat or send it to someone.
Tempo, swing, and bars
Tempo runs from 60 to 200 BPM. Bars sets the length of the download, up to 128, without changing the pattern: every bar is the same sixteen steps.
Swing moves every second sixteenth later. At 90 BPM a sixteenth is 167 ms, so 45% swing pushes those notes back 56 ms. The MIDI export keeps the same timing.
Loop or let ring
Loop writes exactly the bars you asked for. A drum that rings past the end of the last bar, such as an open hat on step 15, is already sounding at the start of the file, because that is what plays there when the loop comes round. Drop the file into a sampler or a DAW and it repeats with no gap and no click.
Let ring starts from silence and adds 1.5 seconds after the last bar, enough for the longest tail to decay. Use it for an ending, or for a file that will not be looped.
The six drums
| Drum | How it is made | MIDI note |
|---|---|---|
| Kick | sine falling from about 180 Hz to 48 Hz, with a 1.5 ms noise click | 36 |
| Snare | 180 and 330 Hz tones under high-passed noise | 38 |
| Clap | three noise bursts about 11 ms apart, then a short room tail | 39 |
| Closed hat | bright noise with the TR-808’s six square oscillators | 42 |
| Open hat | the closed hat with a longer decay, choked by any later closed hat | 46 |
| Tom | sine falling 60 Hz to its pitch over 60 ms | 45 |
Kick tune, snare tune, and tom tune move each drum in semitones. Kick decay and open hat decay stretch or shorten the tail, from a quarter of the default to three times it.
Levels
Each drum has its own level from -40 to +6 dB, and the drums are summed into one output. A sum above full scale is clipped, which flattens the loudest hits. If the kick sounds square, or your DAW’s meter reads 0 dBFS on every downbeat, lower Output rather than the drums one by one.
Example: a 90 BPM boom bap loop
Start from the Boom bap preset: kick on steps 1, 9, and 11, snare on 5 and 13, closed hats on every eighth, swing 45%. Set Bars to 4 and Loop, then download the WAV at 48 kHz, 24-bit.
For your own samples, download the MIDI file instead and drag it onto a drum rack. The kick, snare, and hats land on their usual pads, swung the same way.