What do you do when you’re a ghost doomed to roam the moody corners of Duncan Sheik’s new musical Whisper House for all eternity? You can blow out candles and knock papers out of people’s hands, but it seems like singing’s the only way to soothe a restless, perished soul. Whisper House has been wandering the earth itself, starting public life as a 2010 album before premiering at the Old Globe in California three years later. It’s unlikely to find a more comfortable home than at The Other Palace where Andrew Riley has constructed an eerie wooden set that burrows into the stage like a well or a rickety bomb shelter.

This ephemeral slip of a show, with music by Sheik (most famous for the score of Spring Awakening), lyrics by Sheik and Kyle Jarrow, and co-conception with Keith Powell, concerns young Christopher (Stanley Jarvis on press night), who comes to live in the lighthouse of his mysterious, no-nonsense Aunt Lily (Dianne Pilkington) after his father dies in action and his mother goes mad. But things don’t cheer up for Christopher in his creaky new home since this is World War II America at the outset of the Japanese internment, and Aunt Lily clashes with a local xenophobic sheriff (Simon Lipkin) over the fate of Yasuhiro (a very moving Nicholas Goh), the Japanese man who helps her run the lighthouse.

The story itself seems a compelling one, and all of the actors are strong and directed honestly by Adam Lenson, especially Pilkington as wounded, enigmatic Aunt Lily and the appealing Jarvis (age 11) who has been tasked with making the dangerously prejudiced Christopher sympathetic. But Whisper House makes for an uneasy transition from album to stage. Truth be told, it’s more a play-with-music than musical since, with only a few momentary exceptions, the named characters never sing at all. That honour goes instead to a pair of ghosts, played by Simon Bailey and Niamh Perry, who hover around the perimeter of the stage and take up most of the show’s eighty-five minutes of material (the show needlessly elongates itself with an interval that presumably has more to do with drink sales at the bar than storytelling). Bailey and Perry both sing winningly, but they’re not quite captivating enough to merit pausing the show every few minutes to listen to yet another duet about the pleasures and perils of being dead.

Following the dramaturgical lead of Spring Awakening, Sheik’s songs here tend to offer somewhat opaque commentary on the story. Unlike that far superior show, the singers in Whisper House play no actual role in the story being told and as such they rather quickly run out of things to say. We’re told some far-too-complicated tale about who they might be and why they’re there (“a ghost story within a ghost story,” the Sheriff calls it), but it’s never quite clear what we’re meant to think of them or what they have to do with a story that seems to be ultimately about bigotry and shared humanity (it does beg the question why in a piece about racial inclusion, all the songs go to two dead – literally – white people).

There’s a sleepy musical sameness in Sheik’s soft rock tunes, however well-crafted they may be, and the lyrics, ranging from Earth, Wind, and Fire evocations like, “Remember September/And how it feels” to a bizarrely peppy post-curtain call finale with the clunky message, “If you have a bell/Let it ring/You’re alive/You should sing/But the show’s over for now/Take a bow,” often sit lugubriously over the luxuriating, slow-motion melodies.

Luckily, though, Sheik’s score still registers as something very special indeed because of the exquisite orchestrations by Jason Hart and Simon Hale. Daniel A. Weiss conducts the seven-piece band, and, while it’s unusual to single out musicians by name, it would be remiss not to mention the superb playing of a potent and exposed wind/brass trio early on in the show by Tom Bettley (French horn), Sarah Campbell (trumpet), and Chris Hatton (clarinet).

That magical musical moment is haunting in its yearning urgency and striking strangeness: if only the rest of Whisper House could summon up such potent, poignant phantoms.

Whisper House is playing at The Other Palace until May 27.