DigiTech's HammerOn treats the footswitch like a fret: press it and your note jumps instantly to a chosen interval, anywhere across four octaves, then releases back. That one idea yields seven effects — instant harmonies, octave stabs, tap-tempo trills, and sequenced techno pitch patterns — all playable in real time with your foot while your hands keep playing. The pedal for riffs no fingers can reach.

• Foot-triggered pitch jumps
• 4-octave range
• Tap-tempo trill
• 7 modes