Best known as the guy who wrote Eric Clapton's ''After Midnight,'' JJ Cale has been releasing his own supremely mellow blues-rock records for nearly 40 years. So the fact that he just turned 70 is hardly an issue here; old-guy music is the only kind Cale knows how to make. Roll On is best at its loosest, as in opener ''Who Knew,'' where Cale accents a throwaway jazz lick with some appealingly goofy scat singing, and the title track, which sports a sweet Clapton solo atop Cale's rambling roadhouse groove. B
Download This: Listen to the song ''Who Knew'' on the singer's MySpace
