Mississippi blues seems to be alive and well, judging from Bradley Beesley’s video documentary on Fat Possum Records. The camera work and editing are indifferent, but bland technique can’t hide the spirit of musicians like R.L. Burnside, T-Model Ford, and Cedell Davis, captured in terse bits of dialogue and generous performance sequences of their deeply felt, relatively uncommercial music. Davis, crippled by polio as a boy, plays with the aid of a table knife in his partially paralyzed hand, yet there’s nothing strained about his performance: his solution is only one example of the way these musicians have incorporated hardship into their playing.