Bassist Bill Laswell was always a traveler between musical worlds. A sideman for Mick Jagger and Herbie Hancock, he also led his own avant-rock band in the ’80s called Material, performed with Moroccan tribal musicians and guested with Laurie Anderson. Drummer Milford Graves has kept to a steadier road on jazz’s more venturesome direction, working with everyone from Albert Ayler to Sonny Sharrock. The Graves-Laswell collaboration is a set of extended improvised duets. Running with their instrumental prowess along easy if sometimes quietly furious grooves, their music suggests the tonalities of rock and gamelan, and rhythms associated with jazz, but without adhering to any genre.