Cha-cha-cha (usually shortened to "cha-cha") is a mid-1950s Cuban rhythm developed by Enrique Jorrín in the danzón tradition. It was — and still is — Latin music's easiest export: it sits in a comfortable medium tempo (♩=88–132), it pulses in four (not the brisk "in two" feel of mambo), and the rock-flavoured backbeat on 2 and 4 already lives inside it. If you've played any rock or pop, your hands almost know cha-cha already.
Cha-cha is built around the cha-cha bell: a small, high-pitched cowbell that rings out steady quarter notes. On the kit, you can play those quarters on a closed hi-hat, on the bell of the ride, on a small mounted cowbell, or even on the side of the floor tom. The point is a steady quarter-note pulse on a high, bright voice. Underneath it, the kick provides the bottom and the cross-stick provides the backbeat.
The Cha-Cha-Cha Kick Figure
The genre's name comes from a kick-foot rhythm at the end of the bar — "cha · cha · cha" — that lands on beat 4, the &-of-4, and beat 1 of the next bar. Three quick kicks straddling the barline. That is the whole hook of the rhythm, and you'll hear it in every cha-cha tune ever recorded.
Exercises
The high x noteheads are the cha-cha bell — quarter notes on a cowbell or ride bell, struck with the shoulder of the stick for a clear ping. The c/5 notes on 2 and 4 are cross-stick clicks. Hands only for now; no feet.
Single kick on beat 1. That's it. Cha-cha's bottom is sparse — the bell carries the time, the cross-stick carries the backbeat, the kick just stamps the downbeat. Some players add a second kick on beat 3 as well; try it if it feels good, but a single kick on 1 is the more authentic Cuban sound.
Now the genre's name appears in the foot. Kick on beat 1 (the regular downbeat), then cha · cha on beat 4 and the &-of-4 — two quick 8ths at the end of the bar. When the bar repeats, the next kick on beat 1 is the third cha of the figure: cha · cha · cha straddles the barline. Say it out loud while you play and the foot will fall in line.
Full cha-cha pattern. Hi-hat foot on 2 and 4 reinforces the cross-stick backbeat (a chick under each click). The kick on the &-of-4 happens with the hi-hat foot still down on 4 — that's why the notation shows them stacked. Loop this for two minutes; this is the production-ready cha-cha groove and it should feel comfortable, almost lazy. If it feels frantic, the tempo is too high — drop to ♩=92.