Sondheim is witty and insightful in his commentary about himself and his work. He doesn't say much about his personal life, and it is clear his mother's hostility towards him had a deep effect. (She wrote him a letter before she was undergoing surgery saying that the only thing she regretted in life was having him.) I did find myself wondering about his father, who ran off with another woman when Sondheim was 10 years old. About the only positive out of his childhood was his mother's snobbery leading her to more or less pawn him off on Oscar Hammerstein.
I'm glad the show took a non-chronological approach to his music. There was an interesting mix of familiar and unfamiliar. In the first act, they played with the most familiar by using a bunch of clips from YouTube of different performers doing a line each of "Send in the Clowns," but we weren't spared hearing it in its full glory in the second act. (I don't hate the song, but I do think it's overdone.) There were a few pieces from Passion (a show I don't much care for) and nothing from Pacific Overtures. That's a pity because its score has a few songs that I think illustrate key attributes of Sondheim's music. For example, the simplicity of "A Bowler Hat" leads to a lot of revelations of the character's changes as time goes on. "Please, Hello" is a brilliant pastiche. And the rhyming in "Chrysanthemum Tea" is very characteristic ("it's an herb that's superb for disturbances at sea").
But apparently mine is a minority opinion and I am supposed to be writing about the show, not the songs that aren't in it. The most unusual choice was including "The Wedding is Off" instead of "Not Getting Married," which replaced it in Company. The latter is definitely the more brilliant song, but it is overused. There was a fair amount of material from Merrily We Roll Along and it was interesting to hear Sondheim say that "Opening Doors" was his only autobiographical song. There was one new song for the show. In "G-d," Sondheim plays with his reputation. A page from a 1994 New York Magazine article titled "Is Sondhem G-d?" is projected on the screen, while the performers sing lines like "Still you have to have something to believe in /Something to appropriate / Emulate /Overrate / Might as well be Stephen." Yes, he really did rhyme "believe in" and "Stephen."
As for the performances, Barbara Cook gets a lot of the comedy gold. But I was most impressed with Vanessa Williams, who did a wonderful job with "Ah, But Underneath" (from the London production of Follies) and just as fine a rendition of "Losing My Mind." The other lead is Tom Wopat and I found him disappointing. He didn't seem menacing enough in his performance of "Epiphany" (from Sweeney Todd) and didn't come across as cynical enough when he sang "Happily Ever After" (cut from Company). He did do better singing the Czolgosz role in "The Gun Song" from Assassins, but he was, overall, the weak link. None of the other five performers stood out enough for me to comment on them.
Overall, I enjoyed the show. But I am a theatre geek and a Sondheim fan. I overheard a couple in front of me complaining that they didn't understand the show. I'm not sure there is enough here for me to recommend it to people who aren't at least moderately into musicals to begin with. Could Mr. and Mrs. Out-of-Towner who have seen two Broadway musicals ever find much to care about when Sondheim explains that Do I Hear a Waltz? was unnecessary and he regrets the time spent on it? (For me, this was one of the most provocative statements he made, as I found myself reflecting on why a show should or shouldn't be a musical. My short answer is that music is a particularly effective shorthand to illustrate emotion. But I suspect a lot of current producers just think of the potential monetary reward from cheesy musicalizations of cartoons and TV shows.) They might laugh at an anecdote about Ethel Merman's cussing, but would they grasp the importance of how opening numbers set the tone of a show as illustrated by the three opening numbers used for A Funny Thing Happened on the Way to the Forum? If one is not already a fan, it would probably be better to go to a good production of one of Sondheim's shows instead of seeing this. I recommend Pacific Overtures.
(Actually, I don't, because it has an unimpressive book, but it really does have a lovely score.)