A tempo-synced square-wave LFO on pitch produces a rhythmic octave-jumping lead

The grime melodic lead (heard in Wiley’s ‘Pies’) toggles rapidly between a root note and the octave above, giving a rhythmically active two-pitch figure. This is achieved not by playing two notes but by routing a square-wave LFO to pitch with a depth of one octave and syncing the LFO rate to host tempo. Because a square LFO switches instantly between its two levels, the pitch jumps cleanly between root and octave in time with the track; a sine LFO would instead glide continuously and blur the two pitches. The rate relative to the beat subdivision sets the rhythmic character. The technique needs a tempo-synced LFO on a single held note.

Examples

In the Korg M1’s Pan Flute patch (Woodwind bank), disable insert FX, open the Pitch MG panel, set the waveform to square, Delay 0, Intensity ~50 (an octave of modulation), and enable Tempo Sync; the Freq knob sets the rate. Holding one note makes the pitch jump between the note and its octave on each beat — the ‘Pies’ lead.

Assessment

Recreate the octave-jumping lead with a tempo-synced square LFO on any synth. Explain why a square LFO is required rather than a sine for a clean octave jump. Try different sync rates (1/4, 1/8, 1/16) and describe how the rhythm changes.