DiFranco's music is getting as prickly and complex as her worldview. She's always been a singer-songwriter with a taste for grooves, a nimble acoustic guitarist plucking out riffs for the funk of it. Now she's added more depth to her aggro-folk. On tracks like ''Promised Land'' and ''Shrug,'' DiFranco's barbed vocals glide over breezy horn arrangements and odd-metered jazz beats. She is to Norah Jones what Ornette Coleman is to Kenny G.