A very different type of music documentary, Kurt Cobain: About a Son, also premieres on DVD today, which makes me happy because I've heard so many good things about it but haven't had an opportunity to see it. A. J. Schnack constructed his film based on 25 hours of audio interviews with the late musician. You can read more about the release at Schnack's blog, All these wonderful things. The DVD from Shout! Factory includes selected scene commentary, a "making of" feature, and more from the Cobain interviews.
Barbet Schroeder may be better known for his narrative features (Reversal of Fortune, Barfly) but he's also a skilled documentarian (General Idi Amin Dada, Koko, a Talking Gorilla). His latest, Terror's Advocate, essays French lawyer Jacques Vergès, who has defended people of every stripe, from accused terrorists to Klaus Barbie. Look for the DVD from Magnolia; their web site doesn't have any information on additional features.