With the renewal of interest in the composer and lyricist Frank Loesser over the past decade — successful revivals of The Most Happy Fella, How To Succeed in Business Without Really Trying, and, of course, Guys and Dolls have all been mounted on Broadway — it’s surprising that so little attention has been given to his first show, Where’s Charley? Adapted by George Abbott from the warhorse English farce Charley’s Aunt, which is set at Oxford in the 1890s, Where’s Charley? was written for Ray Bolger. On stage in 1948 and 1951 and on screen in 1952, Bolger played the resourceful undergrad Charley Wykeham, who impersonates his own aunt so that he and his roommate can entertain their girlfriends despite the absence of their intended chaperone. It’s a silly-sweet musical comedy with a charming score, but aside from a 1991 local production (at North Shore Music Theatre, featuring Loesser’s widow, Jo Sullivan, and their daughter, Emily Loesser), it’s been off the boards in this country since Raúl Julia took on the title role at Circle in the Square nearly 30 years ago.

To the vocal delight of the opening-night audience at the Williamstown Theatre Festival, Bolger’s legacy has been passed on to Christopher Fitzgerald in Nicholas Martin’s new production. Only in Williamstown would the leprechaunish Fitzgerald (returning for his eighth season with the company) receive an ovation on his first entrance, though he’s a performer who deserves to be better known outside the Berkshires. With his trademark baby-faced impishness, slightly befuddled concentration (like Chaplin’s), and offhand distractedness, he’s a complete reason for the trip up Route 2, especially when he pours milk and tea into the top hat of his beloved’s stormy-browed uncle (Paxton Whitehead) — who thinks he’s romancing Charley’s aunt, a rich Brazilian widow — or duets with Jessica Stone on " Make a Miracle. " He even meets the challenge of Bolger’s signature sing-along number, " Once in Love with Amy, " by making it all his own.

Jessica Stone (Betty in Betty’s Summer Vacation, also for Martin, at the Huntington Theatre Company last season) plays Amy as a husky-voiced kewpie doll with moments of high-flying madness. She shifts tones and styles with dizzying speed in her first-act solo, " The Woman in His Room, " where Amy, baffled by her swain’s frequent unexplained absences (while he’s swanning about in matronly drag), vents her jealousy in an extended query as to the identity of a girl in a photograph on Charley’s piano. The production’s other musical highlight is " Serenade with Asides " by Whitehead, whose booming bass voice suggests brass cloaked in velvet.

The enchanting work by these three performers rescues an otherwise tacky season opener for Williamstown. The contributions by the usually first-rate set and costume designers, James Noone and Michael Krass, are ugly and look thrown together. Did Krass somehow miss the fact that the musical is set in the late 19th century? Some of the women wear skirts cut high enough for the Roaring Twenties, and the make-up and hairstyle of one of the chorines make her look like a suburban deb expecting her prom date. Hernando Cortez’s choreography — boys and girls leaping from the wings at unlikely moments and twirling each other across the set — dredges up every terrible movie musical you caught on TV as a kid and thought you’d repressed. And except for Simon Jones as the golddigging father of Charley’s roommate, the rest of the cast isn’t memorable.

This is the rare musical comedy in which the leads are comedians supporting a straight romantic pair instead of the other way around, and though that’s a good scheme, perhaps no one can do much with the second-banana roles (here played by David Turner and Sara Schmidt). But it was an unfortunate choice to cast Becky Ann Baker as the real Charley’s aunt: she can neither sing nor act the role, and she looks as if she knew how wrong she is for it. Still, when Fitzgerald, Stone, or Whitehead is on stage, the inadequacies of the production are shoved into the background, if not buried entirely, and Loesser & Abbott’s lovely, inconsequential little show is sweetly served.