In techno a lowpass filter opening over 32 bars is itself the arrangement, replacing chord changes

In techno the primary expressive gesture is timbral, not harmonic: ‘a filter opening over 32 bars is the arrangement.’ Lowpass-sweep and resonance automation take the structural role that chord progressions play in house. The producer’s job is to sculpt the filter envelope over very long timescales rather than to write chords — tension and release run through the frequency spectrum (closed filter, opening filter, peak, re-closing) instead of through harmonic function. Resonant-filter sweeps on dark, distorted, metallic material complete the palette.

Examples

lpf(sine.range(200, 8000).slow(64)) on the main drone creates a slow filter arc that is the arrangement — the notes never change, the cutoff does.

Assessment

In a techno track, what parameter substitutes for a chord change as the vehicle for tension and release? Over roughly how many bars does the source say a filter opening can span the arrangement?