Filter
Low-pass filter. The second argument is cutoff, normally a normalized value around 0.0 to 0.5, and the third argument controls resonance/Q. The suffix 1 selects an independent filter state, so several copies can be used without sharing memory.
Cutoff is normalized; start around 0.02 to 0.35 for musical results. Resonance/Q is typically 0.0 to 0.9. Keep extreme feedback/resonance values under control.
lp1(saw(X), 0.04+0.32*param(2), 0.18+0.55*param(3))
For pitched oscillator functions, X already contains the current MIDI note pitch and transpose information. Prefer saw(X), sin(X), or pwm(X, 0.4) unless you intentionally want an octave or ratio shift such as 0.5*X or 2*X.