In Back from Broadway, Hershey Felder and James Barbour talk, with considerable earnestness and intensity, about their struggle to become Broadway stars — except that they’re not. This ingenuous compilation of biographical confidences and musical-theater standards by " an actor who sings with his voice and an actor who sings with his fingers " is rivetingly self-indulgent, though its perpetrators are certainly talented. Felder is the singing concert pianist and creator of George Gershwin Alone, the one-man show about the great American composer that was a runaway hit at the Loeb Drama Center this summer and fall. Barbour, whom Felder befriended when they were performing in adjacent Los Angeles theaters, is a recent, if hardly a marquee, Broadway leading man. He played Mr. Rochester in the musicalization of Jane Eyre and has also done Broadway stints as the Beast in Beauty and the Beast and Billy Bigelow in the Nicholas Hytner revival of Carousel.

Felder and Barbour take the undressed stage of the Stuart Street Playhouse, which is cluttered and dominated by a Steinway grand, with the pianist dapper in a black shirt and a Kenneth Cole suit, the singer exuding a brooding casualness in black jeans and turtleneck. After some initial banter about how they met in a toilet and a bit of Rodgers and Hammerstein, Barbour starts to mix metaphors like a Cuisinart, informing us that theater’s a tough business, " but once you’re bitten by the bug, you’re hooked. " And that’s nothing to his later assertion that you have to " take the risk and cross through the looking glass " to board " the roller-coaster of uncertainty. " Thank God he can sing and doesn’t write the lyrics that make the whole world cringe. In the course of the evening, the performer knocks our socks off with oversold but nonetheless electrifying renditions of " Soliloquy " from Carousel and " Molasses T’Rum " from 1776.

Barbour’s spectacular vocals, along with Felder’s bouncier piano-driven numbers, are woven into a tapestry of mostly cliché’d anecdotes and banal homages to " the magical, mystical place we call Broadway " from both performers. " Molasses T’Rum, " for example, is a favorite audition piece of Barbour’s, and it becomes the triumphant punch line of a demeaning tale about a longshot cattle call. Felder, probably with his revered Gershwin spinning in the grave, volunteers the dubious revelation that he first got hooked on (or perhaps bit by) Broadway after demanding tickets to Cats as a bar mitzvah gift, then launches into the elaborate lyric of " Jellicle Songs for Jellicle Cats " interspersed with " Memory. " His singing, by and large, is more tossed off and less forced here than in George Gershwin Alone, from which the actor/pianist recycles his dramatic frontal assault on that lush, edgy icon of American tunesmithery, " Rhapsody in Blue " (nicely supplied with a blue hue by lighting designer J. Kent Inasy). Following this committed performance, even the irrepressible Felder seems shaken.

Indeed, both performers follow their more draining musical efforts with displays of visible recovery that come across as melodramatic. Barbour, when not unleashing melodic thunder from that impressive baritone, tends to close his eyes to affect either trance or tenderness. This might communicate less pretentiously in a Broadway theater than it does from the small stage of the Stuart Street Playhouse. Note to director Joel Zwick (who also helmed George Gershwin Alone and the hit film My Big Fat Greek Wedding): try toning these guys down, lest the medics be called in.

Although no one would argue with the power of Billy Bigelow’s " Soliloquy " or with the lyrical durability of My Fair Lady’s " On the Street Where You Live, " there is little newer music here. Barbour delivers a disarmingly crystalline rendition of Craig Carnelia’s baseball fantasy, " What You Call a Dream, " from Diamonds, but too much of Back from Broadway tends toward the bellicose sentimentality of " Climb Every Mountain " and " The Impossible Dream. " Even Mandy Patinkin, from whom you expect an evening of Me-ness, throws some novelty into the mix of talent, ego, and awe.