Claves play the clave. The first is the name of the instrument and the second is the name of the rhythm. Not all claves are played by claves. Clave as a rhythm is applicable to several different rhythms throughout Afro-Cuban folklore and rumba in particular. This blog is mainly about rumba instruments (at least at present).
Rumba is primarily 4 rhythms; yambu, guaguanco, columbia and guarapachangeo. All of these rhythms, except columbia use a pair of claves to play the clave. Columbia traditionally uses a bell to play the clave for that rhythm. Columbia's clave pattern is usually referred to as "the bell" or "la campana" in spanish and more technically as the 6/8 bell, or "seis por ocho".
Guaguanco and guarapachangeo use the rumba clave. Yambu is special as there are 3 different claves that can be played with the rhythm; son clave, rumba clave and "yambu" clave.
"Yambu" clave is similar to rumba clave with additional strikes occuring on the downbeats after the 2nd and 3rd strike of rumba clave.
Anyways, back to the instrument; claves. Usually these are made of wood, but practically anything with a cutting enough sound will work. Currently solid claves made of rosewood or other dense heavy woods are highly available. This kind of clave gives a very high and bright tone. I don't really like it. I prefer hollow claves. LP and other companies refer to these as African claves, for some reason known only to them.
To get the best sound from a set of claves the hand holding the piece that is struck should be cupped and hollow to allow the sound to resonate.
For the best musical results, I like it when the claves and the gua gua or cata have different pitches. My guaguas are pitched a little high, because my claves are hollow and a little lower pitch. The reverse approach is just as acceptable, low guagua and higher claves. You can hear examples of both approached on rumba recordings. If these two instruments have the same pitch it can become a little confusing in my opinion, so my approach is to have the two instruments vary in their pitch.
All of my claves are imported, one from Cuba. I don't know what wood they are from. They take a beating for sure. To prolong their life, I coat them in Danish Oil every now and then and sand the splinters out. The dark ones on the left are my favorite, they have a crisp and hollow sound. Make sure whatever claves you get are not too heavy and sound good, you will probably end up playing them and hearing them for a long time.
For some really detailed information on clave as a rhythm visit my friend's blog: