How the groove generator works
Each style is a groove played by a drum kit or by several percussion instruments, and every hit is a recording of a real instrument, with several strokes per instrument and more than one sample per stroke. You can turn each instrument on or off and set its volume, change the tempo while it plays, and download whole bars as MP3 or WAV. On a keyboard, the Space bar starts and stops the groove.
Every hit lands exactly on its place in the grid, at the dynamic the pattern sets, both when it plays and in the downloads. What keeps it from sounding repetitive is the recordings themselves: a repeated stroke alternates between several samples of the same instrument.
Available styles
Choose the style in the Style menu above. There are five for now, Catalan rumba, rock, funk, jazz and metal, and new ones will be added over time.
Catalan rumba
The rumba of Barcelona’s Romani community, born in the 1950s and 60s with El Pescaílla and Peret. Hand claps, bongos, congas and cowbell back up the guitar’s ventilador, in 4/4 and usually between 100 and 140 BPM. The bell follows a 2‑3 clave.
Rock
A real drum kit in a room playing the basic rock beat: kick on 1 and 3, snare on 2 and 4 and hi-hat in eighth notes. It has a fill with a crash every 4 or 8 bars, an optional tambourine and goes from 60 to 200 BPM.
Rock drum backing track: pattern, fills, tempos and exercises
Funk
The groove of James Brown and The Meters: accented sixteenth-note hi-hat, a syncopated kick and the snare on 2 and 4 surrounded by ghost notes, very soft strokes recorded as such. It has a fill every 4 or 8 bars, a swing control to lay the sixteenths back, optional tambourine and congas, and goes from 60 to 130 BPM.
Funk drum backing track: pattern, ghost notes, swing and exercises
Jazz
A jazz drummer playing medium swing: the ride with its “ding, ding-da-ding”, the hi-hat foot on 2 and 4, the kick barely audible on all four beats and the snare commenting in a fixed four-bar cycle. It runs on a triplet grid, with sticks or brushes and swing set automatically from the tempo or by hand, from 60 to 280 BPM.
Jazz drum backing track: the ride, swing, tempos and exercises
Metal
A metal kit with a punchy kick, a brass snare, a china and bright cymbals. It has three grooves in the Groove menu: sixteenth-note double bass with alternating feet, the thrash skank beat, and a heavy half-time breakdown. It has a fill every 4 or 8 bars and goes from 60 to 240 BPM.
Metal drum backing track: double bass, thrash, half-time and exercises
How to practise with a groove
- Start slow. Set the tempo well below the song, for example 90–100 BPM, and play the song or your part until it sits with the groove.
- Find the anchor. In every style there is a beat where the strongest hits meet; in Catalan rumba it is beat 4, with the loudest clap and the open tones of the bongos and the congas, in rock and funk it is 2 and 4, with the snare, in jazz it is the hi-hat foot on 2 and 4, and in metal it is the snare rimshot on 2 and 4 (on 3 in the half-time). If you drift, listen for it and land there.
- Strip it down. Turn instruments off one at a time and keep the feel. With only one left, you carry the groove yourself.
- Speed up gradually. Raise the tempo 5 BPM at a time up to the speed of the song.
- Take it with you. Download 1 to 10 minutes as MP3 or WAV to practise away from the screen or to load it into your recording software.
To check that your time holds without help, combine it with the gap click metronome, which goes silent for whole bars.
Frequently asked questions
Is the groove generator free? Can I use the files I download?
Yes. It is free and there is no account to create. The samples are public domain (CC0) and the file is generated on your device, so you can use it to practise, in lessons or in your own recordings.
Are these real instruments?
Yes. Every hit is a recording of a real instrument, with several strokes per instrument (for example open tone, slap and heel on the conga, or closed, open and pedal hi-hat) and more than one sample per stroke, so the loop does not sound mechanical. The drums also have separate recordings for soft and hard hits, because a snare played softly does not just sound quieter: it sounds different.
What tempo range does each style have?
Each style has its own range and starting tempo, always counting quarter notes. Catalan rumba is usually played between 100 and 140 BPM; here it goes from 70 BPM, for slow practice, up to 220 BPM, and starts at 140. Rock goes from 60 to 200 BPM and starts at 100, a comfortable mid-tempo. Funk goes from 60 to 130 BPM and starts at 95, where the sixteenths come through clearly. Jazz goes from 60 to 280 BPM and starts at 130, a medium swing. Metal goes from 60 to 240 BPM and starts at 120, a comfortable double bass to begin with.
Why is the download a little longer than the length I chose?
The file always contains whole bars and ends with a final hit on beat 1 that is left to ring out, so it never cuts a note in half. That adds up to one bar and a few seconds, the time the last hit takes to fade (the rock crash takes the longest).
Are there keyboard shortcuts?
Yes. Press Space to play or stop the groove, just like the Play button, and the page will not scroll. It does nothing while you type in a field, when a menu, slider, switch, button or link has the focus (Space keeps its usual job there) or together with Ctrl, Cmd, Alt or Shift, so it does not clash with your browser’s shortcuts.
Can I change the tempo or the instruments while it plays?
Yes. Tempo, instruments, volumes, fills, swing, groove and sound change straight away, without stopping the groove. Changing the style restarts it.
Does it work on my phone and offline?
Yes. It works in the browser on phones, tablets and computers. On iPhone, tap Play to start the sound. After your first visit the groove also plays without a connection.
What is swing, and which styles have it?
Swing delays the off-beat notes a little so the groove feels laid back instead of straight. The percentage says where that note lands within its beat or its pair of notes: at 50% it is straight, at 66.7% it is a triplet and at 75% a dotted eighth. In funk it moves the sixteenths and starts straight; towards 60% it sounds like the more relaxed side of funk and neo-soul. In jazz it moves the eighth notes and starts on automatic: it follows the tempo like a drummer would, heavier at slow tempos, an exact triplet at medium tempo and straighter when fast. You can also set it by hand.
Will there be more styles?
Yes. Each style is a simple data file, and more grooves, such as bossa nova and reggae, will be added.