We don't often recommend movies featuring blackface, but this 1927 talkie, which follows a cantor’s son as he becomes a minstrel, is one of the ultimate, protomythic American stories. Al Jolson’s mimicry is wildly discomforting — and crucial to witness. The extras on this three-disc set downplay the love-and-theft paradox of minstrelsy and focus instead on the innovation of sound pictures, with a lovely collection of early Vitaphone shorts; they're fascinating, but no match for the power of the movie itself.