In the show's most complex numbers, people operating in totally different musical modes (and often at emotional, racial, and generational loggerheads) sing, and the genres, at least, intertwine. Noah likes to join Caroline down among the appliances, even though she gives him little encouragement. She's grouchy with him, but he worships her. Noah — his mother dead, a new stepmother, Rose (Caissie Levy), trying to take her place — clearly wishes Caroline could rule over him solely and absolutely. (Three actors alternate in Noah's role. I saw Adam Makké.) His father, Stuart (John Cariani), doesn't always remember how old his own child is, whereas Caroline has her children always on her mind, wondering how to stretch her $30 a week to take care of her teenage daughter, Emmie (Samantha Williams), and little Jackie and Joe. One day, feeling awkward about money, Rose decides to discipline Noah for his habit of leaving change in his pockets by telling Caroline she can keep anything she finds in the laundry. "It'll be like a raise! Like Noah pays a share of your salary," she warbles unconfidently. When Rose's father visits, he notices right away that she has accidentally-on-purpose driven a wedge between Noah and Caroline, whose humiliation and need and rage add up and up, as do the quarters in the cup on the washing machine. Michael Longhurst's production has traveled far to get here. A rousing 2017 success at the Minerva in Chichester led to a run in London's West End, and that (mostly recast) show and its star, Clarke, now comes to the Roundabout. All the performers here are superbly married to their material, matching strengths to strengths but also — and most movingly — flaws to flaws. N'Kenge's voice as the Moon is soaring, pure, effortless, gorgeous. Cariani sounds strained when he sings to Noah but passionate and free when he's playing his beloved clarinet. (Cariani is actually playing the clarinet, not pretending.) Tamika Lawrence, playing Caroline's friend Dotty, and Williams both have voices like trumpets, as clear and untethered as their characters' optimism. But Clarke's voice seems to be dragged out of her almost against her will. You can hear weariness in it the bigger it gets; you can hear gravel and blood. When the original U.S. production of Caroline, or Change came to Broadway from the Public in 2004, it was critically beloved but not financially successful.