Models

Ace Tone Rhythm Ace FR-1

The preset rhythm box the whole category descends from

Drum machine · Japan

Ikutaro Kakehashi's Rhythm Ace played fixed patterns — bossa nova, waltz, march — from transistor circuits, with buttons you could press in combination. It was built to accompany organists, and it is the direct ancestor of everything below: Kakehashi founded Roland four years later.