I heartily endorse everything that the previous reviewer has written.
It's funny how some movies that were not popular on release become cult classics, yet others like this one, that were huge hits and received critical acclaim and awards, fade into obscurity. As a biopic it was wildly inaccurate, but most Hollywood biopics were inaccurate. The real story of Billie Holliday would not have played in 1972! 'Lady Sings The Blues' is still a great movie, and captures Billie's spirit in some ways.
The disc comes with a lot of extras. There are over half an hour of deleted scenes. Having watched the movie so often, I know exactly where they slot in, and it is good to see them after all this time.
There is also an all too short interview with Diana Ross from just a few years ago, talking about the film, and a short feature where people discuss the importance of the film. There is a director's commentary with the two directors, one was Berry Gordy.
The picture quality is excellent, but the disc really is really region 1. For a dedicated Ross fan, it is worth investing in a multi-region DVD player, just to see those deleted scenes.