Called the Circle Guitar and created by [Anthony Dickens], the novel instrument features a constantly-rotating wheel around the guitar’s pickups in the body.

The wheel is controllable via the guitar using tap-tempo, or its dedicated Speed dial. Beyond the guitar, it can be manipulated via MIDI, lending itself to a more tapping-based playing style.

The resulting style of play evolved into slack key—a distinctly Hawaiian sound with complex patterns of rhythm, bass, and a leading melody all handled by one player on an acoustic guitar.