It's almost like being insane, seeing potential squandered by neophytes ill equipped for the hefty task they set for themselves. The York Theatre Company's latest, Asylum: The Strange Case of Mary Lincoln, trumpets its excellent subject matter just as loudly as it does its mediocrity as an entertainment - or educational - property. June Bingham and Carmel Owen's brilliant idea for a chamber opera has become, in their inexperienced hands, a dull and dreary treatise on the unsavory aftermath of one of America's most mythic (and misunderstood) families.

One can easily imagine the story of Abraham Lincoln's widow, and her struggles against an ungrateful son she believes has wrongfully imprisoned her in an Illinois mental institution, as a panoramic exploration of personal and political history as seen through the lens of a famous brood feuding in the public eye. Asylum, however, looks only inward, and finds little worth writing home about. The central relationship between Mary (Carolann Page) and her son Robert (Edwin Cahill) is at best lightly sketched, and Bingham's book does little to mask the odor of eraser dust.

Bingham presents him as stiff and stodgy, a would-be politician incapable of being judged on terms other than his father's, and her as a warm but distant recluse happier to recall her brighter days with her husband than live in the present. The book doesn't go much further: It elaborates little on their conflict's underpinnings, never allowing either to look like more than a faded black-and-white photo. In a more traditional musical, this would scarcely be a cause for concern as the songs could help pick up the slack.

But the focus of Owen's compositions is too narrow, less about enriching characters' personalities than pushing specific narrative buttons more appropriate for a television documentary. Mary and her would-be rescuer, lawyer Myra Bradwell (Bertilla Baker), sing too much about their admiration for the other as a woman of strength. In one of her fantasies, Mary recalls how she convinced her husband (John Jellison) to pursue national politics instead of the governorship of Oregon. The asylum's black nurse Delia (Joy Lynn Matthews) sings two songs of the personal and spiritual freedom Mary should cherish at every opportunity.

Numbers clarifying the difficulties between Robert and Mary are conspicuously absent, preventing the urgency of their ongoing squabblings from taking hold emotionally. Much of their interactions are restricted to awkwardly musical dialogue, almost recitative, in semi-songs with titles like "Mother I Need You," "This Is The Solution," and "Why Robert, Why." While Owen's music, intriguingly orchestrated for piano, violin, and cello, is frequently attractive and occasionally of impressive operatic scope, her lyrics possess none of the penetrative, intellectual character necessary to effectively chronicle any war fought with solely psychological weapons.

At least the songs are sumptuously sung, not least by Page, whose robust mezzo makes one almost - almost - look forward to the next number it will grace. But as the songs are also highly disjointed and often unnecessarily wedded to the action, the cast's impressive vocal gifts don't mean much. They also tend to lack the spark that might make them stand out from director Fabrizio Melano's static staging, which often leaves them as stranded as the figures in the larger-than-life portraits constituting most of James Morgan's set.

Of course, Melano's work can only be as animated as his material, which at its best is tightly corseted. Bingham and Owen have yet to discover the freedom music allows storytelling, and thus have themselves become enslaved to it erupting at the wrong moments and telling us too much we don't need to know. They might have profited from first writing a straight play about Mary Lincoln, which might have forced them to unearth their subject's theatricality before risking diffusing with songs. Enlisting the help of an established librettist talented in unconventionally structuring musicals would also have been wise.

In going it alone, Bingham and Owen made an already challenging assignment even more difficult. While their program bios boast previous writing credits, nothing quite suggests their ability or experience to realize a project of this scope. Failing to emancipate characters' inner voices is almost always a sure step toward failure, and that's currently the primary thing that is making Asylum so maddeningly unmusical.

Asylum: The Strange Case of Mary Lincoln
Through October 1
Running Time: 2 hours, with one intermission
Theatre at Saint Peter's Church in the Citicorp Center, 54th Street and Lexington Avenue
Tickets online and current Performance Schedule: SmartTix