If Odean Pope straddles the line between hard bop and free jazz, Chris Kelsey, who sometimes authors this column, plays forthright avant-garde soprano saxophone. He also writes idiomatically appropriate compositions (some of them stop-and-go evocations of Ornette Coleman) as improvisational inspiration for his and his colleagues' probing flights of fancy. On Renewal (CIMP), Kelsey uses a pianoless quartet, featuring trombonist Steve Swell, a musical soul mate from earlier sessions; the like-minded Francois Grillot and Jay Rosen handle the bass and drums duties, respectively. On five extended tracks (most of them between 12 and 18 minutes long and often sectionalized), the performers create a diversity of textures and moods. At one point in "Charlie Parker's Last Will and Testament," for example, Kelsey shifts from anguished cries and swirling clouds of notes to a spot of boplike phrasing over a steady, swinging beat. But most often, he and Swell and the others employ the sounds and techniques of free jazz to generate an exhilarating high-energy interaction, which is especially electrifying in those sections where the four performers engage in virtuosic collective improvisation.