All Our Children, the first play by the experienced theater and opera director Stephen Unwin, is structured as a moral debate that sheds light on the mass murder of disabled children in Nazi Germany. The play is well-staged and intermittently powerful, but overly schematic, as the characters too often feel like mouthpieces rather than fully realized individuals. It premiered on the West End in London in 2017, and now comes to the Black Box Theater at the Sheen Center, with a new cast, under the sure-handed direction of Ethan McSweeny.

By the time of Oscar Hammerstein II’s death, in August of 1960, The Twilight Zone had completed its first season on CBS, and The Lawrence Welk Show was six seasons into its 16-year run on ABC. It’s worth noting this not because one of the theater’s greatest librettists was a known fan of either TV show, but because both programs may come jarringly to mind at Doreen Taylor’s Sincerely, Oscar, a combination memoir and homage that celebrates the talent, and apparent immortality, of the man whose timeless work ranges from “Oh, What a Beautiful Mornin’” to “Some Enchanted Evening.”

No one attends the symphony for a surprise ending, or to watch the string section go rogue. The enjoyment lies in the way that each instrument performs as expected, to the height of the players’ abilities, creating controlled harmonies and disciplined rhythms that pull at the heart while being pleasing to the ear. So it is with Mrs. Murray’s Menagerie, the absorbing new comedy from The Mad Ones that finds six parents, each with an instantly recognizable personality, playing off one another during a market-research session at a pace that can only be described as musical.

Charlie’s Waiting, a new dark comedy by Mêlisa Annis, demonstrates its young author’s flair for weaving comedy and drama together, as well as a wicked imagination. The “what if” behind the plot creates tension that is palpable.

You’ve probably heard the story, or maybe you saw the Tim Robbins movie. In 1937, the WPA shut down the Federal Theatre Project’s new “play in music” four days before opening, fearing that its radicalism and pro-union message were just too incendiary. John Houseman (producer), Orson Welles (director), and Marc Blitzstein (author ) were determined to put it on somehow. On opening night, forbidden from using the designated theater and lacking an orchestra, they sent an actor out to find a piano. The audience was marched 21 blocks to another, vacant theater somebody else had found. Not allowed to appear onstage, the actors performed from the house, with Blitzstein, the only nonunion performer, playing the score from the stage. The effect was electrifying, and The Cradle Will Rock went on to find other backing and enjoy a successful, conventionally staged run.