Master jazz bassist Richard Davis teams up with the esteemed John Hicks on piano for a round of sensitive duets. With a rapport that is truly rare, the two play music that spans genres from classical to bebop to spirituals and vintage blues. Davis is especially moving on Ellington's "Warm Valley" and Strayhorn's "A Flower Is a Lovesome Thing," the latter sounding as though it were written specifically for bowed bass. Moving freely and elegantly between arco and pizzicato, Davis possesses a virtuosity that remains undimmed. His music takes him through a wide swath of emotional terrain, from the dead-serious mood of his unaccompanied "Go Down Moses" to the lighthearted spoken-word ending of "C.C. Rider." This, too, is a part of the "diversity" to which the album title refers. But one ought to read Davis' program notes to see just how expansively he's defining that word.