I recently acquired copies of two monumental books addressing clave and rumba. The first two books in the Unlocking Clave series: The Clave Matrix and Rumba Quinto, both written by California's own rumba researcher; the intrepid David Peñalosa. As these books are the first two in David's "Unlocking Clave" series, I assume there will be more books in the Unlocking Clave series yet to come.
The Clave Matrix has been out for a little while, and Rumba Quinto will be released soon. I was fortunate to get a preliminary copy of that book.
I'm just about through the first book "The Clave Matrix", which has been a very enjoyable study. I'll be posting a review of The Clave Matrix shortly. Later on you can expect a review of Rumba Quinto as well, but one book at a time.
David has made a Facebook album with some of the graphics and images he used for The Clave Matrix, including some great images of Cal Tjader and Tito Puente.