There's something positively electric when he first hear Al Jolson belt out "Dirty Hands, Dirty Face", the first minutes of synchronized sound in a full-length feature. I found it to be captivating, and for me the most memorable moment is the joy of Jolson's mother as he sings "Blue Skies" to her, and the back and forth dialog they have about buying her a pink dress. It's something special when you know about, and the actors are discovering, this new format for movies.
That said, the film's music is the best part, and while the story of a Jewish boy how is forced from his home when his father won't accept his love of jazz is an interesting one, I think it gets a bit slow at times, and overly sentimental. It hardly distracts from this watershed of a film, and I couldn't think of a better choice of the first "talkie" than a musical, particularly jazz.