The new CD by The Derek Truck Band, Already Free, is a good example of how root forms of the blues have been transformed, yet preserved, by rock music.  Trucks has an excellent pedigree in Southern blues-rock, taking up Duane Allman's mantel as the best living slide guitarist and incorporating a range of world music influences into his playing.  An excellent foil to this superb album, Blues Blues Blues is another transformational CD that brought a group of English and American all-stars together with historic bluesman Jimmy Rogers just before he died.