Another bunch of jazz stars influenced by Miles Davis play a bebop rite to the departed lord of the south side of darkness. Herbie Hancock, returning to relatively straight-ahead jazz, sounds just fine. And Wallace Roney, a particularly sharp young trumpet turk, sounds less like Miles than he used to. But what's really the point of performing Davis' old tunes almost as well as he? I mean, aside from putting his name on the cover of the CD?