Play melodic lines and listen for the aggressive bite on each note attack. The ENV 3 sweep creates a timbral arc from bright to dark. Try adding velocity expression (ENV 3 Velocity = 60) so harder playing produces more dramatic sync sweeps. Add Osc Slop = 3 for vintage character.

Hard sync forces Osc 1 to restart every time Osc 2's waveform resets (Anu Kirk p.17-21). When Osc 1 is set higher than Osc 2 (C2 vs C0), the pitch stays locked to Osc 2's frequency while the timbre becomes harmonically complex. ENV 3 sweeps Osc 1's frequency (O1F) with Amount 67, Attack 15, and a long Decay 87 -- this produces the signature Prophet-5 sync sound: an aggressive bite on the attack that gradually settles to a simpler tone. Only Osc 1 is heard (others at Level 0).