All dance music is organized around a steady pulse. But African and Afro-Cuban rhythms are also organized around asymmetrical repeating rhythmic patterns called timelines. The musicians in a group use the timeline as their reference rhythm and play their parts in relation to it.
In Afro-Cuban rhythms, the timeline is called the clave (klah-vay) and it's usually played on two cylindrical pieces of wood called claves:
Claves are ideal for timelines because they produce crisp, penetrating sounds that can be heard above other instruments.
The grooves in this lesson are based on a timeline called the one-bar clave. This popular rhythmic pattern can be found in music all over the world. In cut-time, the one-bar clave is only one measure long. That means it will repeat twice on our two-measure charts.
In the first pattern, you'll play the one-bar clave with basses, filling in the beats in between with touches. Notice that since we're back in cut-time, the pulse is back on 1 and 3:
Here's how the same pattern looks in 4/4:
The one-bar clave gets its tremendous vitality from its uneven-ness. It's like a wheel that's not quite round; it's got a hitch in it. Exactly three beats after the first note comes the second note, and exactly three beats after the second note comes the third. Then comes the hitch. After only two beats, the pattern abruptly starts over again on 1:
Now vary the pattern by replacing the bass on the and of 2 with a slap.