This is the first in the seven-film documentary series The Blues, a Musical Journey: and the only instalment to be directed by the driving force behind it, Martin Scorsese. Tracing the progress and evolution of the music from Mali to the Mississippi, Scorsese never loses sight of the historical legacy of slavery, poverty and repression that underpins its pain and pathos. But he also succeeds in recapturing the mood, method and message of such Delta legends as Robert Johnson and Charley Patton. Guitarist Corey Harris proves an amiable travelling companion - his conversations with the likes of Ali Farka Toure, Taj Mahal and Keb' Mo' are as captivating as the music, which retains all its affecting power.