Jimi Hendrix’s blues tunes feature some of his most tender playing, and some of his most vicious. “Bleeding Heart” is all fire and bluster, with cascading runs of squalling notes, while the acoustic “Hear My Train A-Comin’” is a despondent sigh. His bandmates hold down the groove while he turns the form inside out, as he does on the endlessly inventive “Born Under a Bad Sign”. To hear them suddenly step the pace up a notch at the end of “Catfish Blues” is a giddying thrill.