TheatreWorks stages this musical adaptation of Marivaux's comedy with real imagination and ingenuity. Fumiko Bielefeldt's costumes are beautiful, witty mixtures of 18th-century France and kitschy pop, and Joe Ragey's set wondrously progresses through each of the four seasons, ending with a white Christmas that anticipates a similarly hued wedding. (The smart, innovative concept is local director Danny Scheie's.) Director Robert Kelley conducts his remarkable cast smoothly, but (with two exceptions) the songs, by Jeffrey Stock (music) and Susan Birkenhead (lyrics), ruin everything. They're tuneless and frenetic, with long stretches of frantic patter interspersed with the standard Broadway bellowing. Only "Henchman" -- a vaudeville-style complaint sung by Harlequin (Kirk Herring) and the crude gardener Dimas (Patrick Flick) -- and "Love Won't Take No for an Answer" -- which ends with a comic Mozartian recitativo -- are enjoyable. James Magruder's book smooths out Marivaux's dialogue while slightly complicating his plot. The exiled prince Agis (the dashing Jonathan Rhys Williams) has been raised by the rationalist siblings Hermocrates (Steven Patterson) and Hesione (Livia Genise). Taught to scorn all emotion, he spent his young life planning to oust the Princess Léonide (Debra Wiseman). But the princess, aided by her servant, Corine (C. Kelley Wright), infiltrates Agis' compound in disguise, hoping to win his love and restore him to the throne. Patterson and Genise are moving as people who long ago tried to leave passion behind, only to be thwarted by it now. (Hesione's song "Serenity" should break your heart, but it's bland and unaffecting.) The energetic Wiseman manages well in the dramatic scenes, but her comic sequences show strain. (Léonide's myriad songs continually interrupt, ensuring no actress could succeed in the role.) The show does have its triumphs, but TheatreWorks would have been better off applying its talents to the original Marivaux play, rather than to this labored musical.