Some of the shows he panned over his long career included the musically ambitious shows of Stephen Sondheim. Of Sondheim's Company, Kerr wrote that the show was too cold, cynical and distant for his taste, though he "admitted to admiring large parts of the show." In his review of Sondheim's Follies, he wrote " 'Follies' " is intermissionless and exhausting, an extravaganza that becomes tedious for two simple reasons: Its extravagances have nothing to do with its pebble of a plot; and the plot, which could be wrapped up in approximately two songs, dawdles through 22 before it declares itself done...Mr. Sondheim may be too much a man of the seventies, too present-tense sophisticated...The effort to bind it up inhibits the crackling, open-ended, restlessly varied surges of sound he devised with such distinction for "Company'." He praised A Little Night Music, writing that "The score is a gift, the ladies are delightful, and producer Harold Prince has staged the moody meetings with easy skill." He expressed mixed sentiments about The Demon Barber of Fleet Street, praising the music but deeming it too lilting for the show's grisly subject, and finally writing, "What is this musical about?" As an afterthought, he wrote a follow-up article on his observation that the musical contained a plot from Molière's The School for Wives, posing the question who, of all of the authors who had revised the tale of Sweeney Todd over the years, had put the plot into the story.

Notoriously he is credited with one of the world's shortest reviews "Me no Leica" for John Van Druten's I Am a Camera in the New York Herald Tribune, December 31, 1951.

Nevertheless, in 1977, he wrote of Sondheim "I needn't tell you that Stephen Sondheim is, both musically and lyrically, the most sophisticated composer now working for the Broadway theater."

In reviewing West Side Story he focused on the dancing: "the most savage, restless, electrifying dance patterns we've been exposed to in a dozen seasons...The dancing is it. Don't look for laughter or — for that matter — tears."

In his review of the original 1956 Broadway production of Candide, he wrote that it was a "really spectacular disaster". However, in reviewing the 1973 revival of Candide he wrote that it was a "most satisfying resurrection." " 'Candide' may at last have stumbled into the best of all possible productions...The show is now a carrousel and we are on it quite safely...The design of the unending chase is so firm, the performers are so secure in their climbing and tumbling...that we are able to join the journey and still see it with the detachment that Voltaire prescribes."

Of Frank Loesser's "musical with a lot of music" [sic. opera], The Most Happy Fella he wrote: "the evening at the Imperial is finally heavy with its own inventiveness, weighted down with the variety and fulsomness of a genuinely creative appetite. It's as though Mr. Loesser had written two complete musicals-the operetta and the haymaker-on the same simple play and then crammed them both into a single structure." He wrote a favorable review of The Pajama Game: "a bright, brassy, and jubilantly sassy show [that] takes a whole barrelful of bright new talents, and a handful of stimulating ideas as well, and sends them tumbling in happy profusion over the footlights."

Of Frank D. Gilroy's famous play The Subject Was Roses:"a family triangle in which a father loves a son and the mother loves that son and the son loves both mother and father and not one of them can make a move or utter a sound that does not instantly damage the other."

Books (selected)

• How Not to Write a Play (1955)
• Criticism and Censorship (1957)
• Pieces at Eight (1958)
• The Decline of Pleasure (1962)
• The Theatre in Spite of Itself (1963)
• Tragedy and Comedy (1967)
• Thirty Plays Hath November (1969)
• God on the Gymnasium Floor (1971)
• The Silent Clowns (1975)
• Journey to the Center of the Theater (1979)

Broadway

• Count Me In 1942 musical - wrote book
• Sing Out, Sweet Land 1944 musical revue - wrote book and directed
• The Song of Bernadette 1946 play - wrote book with Jean Kerr and directed
• Touch and Go 1949 musical revue - wrote sketches and lyrics with Jean Kerr and directed
• King of Hearts 1954 play - directed (written by Jean Kerr and Eleanor Brooke)
• Goldilocks 1958 musical - wrote book and lyrics with Jean Kerr and Joan Ford (lyrics) and directed