[Note:  This post deals examines the difference between rumba clavé and bembé clavé.  For the shift from 4/4 to 6/8, see here.]

I had a drum teacher state that the 6/8 clavé was exactly the same as the rumba clavé.  I know he was just trying to help some of the beginners remember how to play the rhythms, but being a bit of a rhythm math geek myself I knew this was technically not true.  In fact, I went to spreadsheet extremes to prove (to myself) that this was not true.

When you look at the doc (if you really care that much), you'll notice that the basic son clavé and the first three beats of the bembé are close, but that the rumba clavé and bembé clavé come really close.

While it's pretty tough to get to that latter level of differentiation, there is a great exercise you can do with the simpler clavés.  Beats two and three of the son clavé and the basic bembé rhythm come close to each other, but that they also dance around the second downbeat of the four-beat count.  So here is an exercise you can do to get the feel of the difference:

• With your dominant hand, play the first three beats of the rumba clavé.
• With your non-dominant hand, play the one and two downbeat.

What you will hear is a ubiquitous 2/2 rhythm, now heard a lot in reggaeton.

Do the same again, but with the first three beats of the bembé pattern.  If you find yourself falling into the same pattern as above, the trick is to think of the simple pattern: LR together, R-L-R, then LR together again (or check out this explanation of the "mother of all polyrhythms").

Now switch back to the rumba clavé exercise, and repeat....

You'll see in the chart that the bembé pattern is pushed forward slightly in comparison to the rumba clavé, and is evenly spaced around the second downbeat.

Once you can feel the difference between these two, it becomes a lot easier to feel the shift from a 4/4 rumba clavé to a 12/8 bembé clavé.

Here are some more sound samples of afro-cuban clavés to help you along.

Finally, please note that I've titled the attached chart a "pedantic" comparison of the clavés, because ultimately, rhythm is about feel.   There really is an enourmous amount of flexibility in rhythm, and in what will work and sound good.  Kim Atkinson once mentioned that he shifts the sounds of the bass drums and the high-pitched drums in his recordings to make the listener perceive them as coming at the same time. There is a school of hip-hop production that "pushes" the down-tempo beats to give the song a forward moving momentum, even though the shift is infinitesimal.  And, perhaps most tricky for me right now is the fact that you can swing 12/8 rhythms (and no, they don't start to turn into 4/4 rhythms).