Acid House
One broken bass machine, and a rhythm track that gets out of its way.
The pattern
1 bar, sixteenth notes. Loops until you stop it.
Sixteen steps, because an acid loop genuinely is one bar and stretching it to two would be padding. Kick on all four beats, clap on 2 and 4, closed hats on every eighth with the offbeats at 88 against 64 on the beat, and one open hat on the last offbeat to mark the turnaround. There is no percussion lane at all, and that is not an omission: the 303 occupies the space a shaker or a conga would take, and filling it is how acid tracks stop sounding like acid tracks.
What it is
In 1986 someone in Chicago pointed a Roland TB-303 at its own filter and turned the resonance up. That is where acid house starts. The machine had been built to fake a bass guitar for musicians practising alone, it was bad at that, and it had been discontinued. Phuture's Acid Tracks made the failure the record. The drum programming underneath is deliberately plain, because the 303 is doing something loud and strange and anything busy in the rhythm section fights it. Britain then took the sound into fields, which is a different story with the same grid.
What it sounds like
A squelching, sliding bassline that never stops moving, over a rhythm track with a kick, a clap and a hat in it and nothing else. The 303 glides between notes because accent and slide are set per step, and the filter opens and closes under your hands while the pattern repeats unchanged. Everything else is dry. No pads, frequently no chords at all, and where there is a vocal it is a shout rather than a melody.
Key elements
- The 303Sixteen steps with accent and slide set per step, played through a filter you keep moving. The performance is the filter, not the notes.
- A rhythm track that stays out of the wayKick, clap, hats, nothing else. Anything more crowds the midrange the 303 needs, and you will end up muting it.
- The offbeat hat accentClosed hats on every eighth with the offbeat clearly louder than the downbeat. That single difference in velocity is where the forward lean comes from.
- One open hat per barA single open hat on the last offbeat, marking the turnaround. Used this sparingly it does more work than four of them would.
- No chordsA great many acid records have no harmony beyond whatever the 303 line implies. That is a choice rather than an oversight, and it works.
How to get them
- 303 or emulationWrite sixteen steps, set accent on about four of them and slide on two, then record several minutes of yourself moving cutoff, resonance and envelope amount. Comp the best two bars out of that.
- Distortion after the filterRun the 303 into an overdrive or a transistor distortion, then a second filter. The classic squelch is mostly what a distorted resonant peak does while the cutoff moves.
- KickA 909 kick with the decay long enough to overlap the following offbeat hat. It should feel like it is holding the 303 down rather than driving it.
- ClapA 909 clap, dry, dead centre, and a touch quieter than feels right in solo. Reverb on the clap is what turns an acid track into a deep house track.
- HatsClosed hats on all eight eighths, offbeats around velocity 88 against 64 on the beat. Save the open hat for the last offbeat of the bar.
- Leave the drums aloneResist adding percussion. The 303 pattern is the arrangement, and every extra element is one more thing competing for the same frequency range.
Reference points
Phuture, DJ Pierre, Armando, Adonis, Hardfloor, and again the Trax catalogue. Named as reference points for the sound, not as endorsements.
The pattern is a starting point rather than a rule. If you want the theory underneath why any of it works, Battuto measures it.