Bass

Acid is a filter, not a note.

You now have: a full drum groove with locks and variation.

This lesson is being written. The outline below is what it will cover.

Planned outline

  • Track 9 is Bass, and it runs the TBD03 — a 303-style acid voice.
  • The thing to notice: TBD03 puts the filter on page 1, before the oscillator. That ordering is the lesson. On this instrument the filter is the sound.
Page 1 knob What it does
Cutoff How open the filter is — the single most important knob on the machine
Reso How much the filter emphasises its own cutoff point — the “squelch”
Env Amt How far each note kicks the cutoff upward
VCF Dec How fast that kick falls back down
  • Why those four together make an acid line: every note opens the filter and it closes again, so a line of identical notes still moves.
  • Writing a bassline that works with the kick: notes on and around the kick, space where the kick isn’t.
  • Accent and Slide — page 3 and page 4. Slide is what makes consecutive notes glide rather than restart, and it’s most of the 303 sound.
  • Choosing notes: root note on the downbeat, octave jumps for energy, a fifth for tension. Starting with three notes is enough.
  • Track 10 is a second Bass track running the same machine — one for the sub, one for the acid line.

The finished exercise will provide a short editable TBD03 line and the four filter controls above, so the learner can hear the acid movement directly.


Next: 9 · Playing it in · Previous: 7 · Parameter locks

Reference: TBD03 · Step editing · Parameter locks