...the premise being that blues and folk have disappeared from the pop/rock scene? Can't accept that. The basic structure is still there - it's just evolved, and continues to evolve. Consider the changes in jazz in the last century from Dixieland to Swing to Bebop to Avant-garde to Fusion to ....it's all still recognizable as jazz.

Blues continues to be incorporated into rock music, and emerging and established artists that are defined as blues musicians are played on rock stations every day (e.g., North Misissippi AllStars, Robert Cray).

Depending on your definition of 'folk' (my definition of folk being very very broad) popular artists like Jewel, Ani DiFranco, Beth Orton, Tracey (sp?) Chapman, Steve Earle, John Hiatt, as well as veterans such as Dylan, Neil Young, James Taylor, continue to work from within the folk structure.