Emotion alone is not enough to make a good musical. If a book and score do not work in concert to elevate their subject they invariably end up wallowing in it, which is exactly the fate that befalls Southern Comfort. Dan Collins and Julianne Wick Davis's new show at CAP21 captures and unleashes a plethora of details that should tug the heartstrings but come closer to drowning you in misery—when they're not putting you to sleep, that is.

In fairness, the concept here is by no means foolproof. The show is based on the 2001 documentary of the same title, which explores the last year or so in the life of female-to-male transsexual Robert Eads: his relationship with the male-to-female transgender Lola, his accumulating and spending time with his "chosen family" of like-minded (and -bodied) friends, and the Southern Comfort Conference in Atlanta that caters exclusively to transgender and transsexual people. On the list of stories that do not instantly scream "musical," this one must be on one of the topmost lines.

The CAP21 production, which Thomas Caruso has lovingly directed, does not disabuse one of the notion that these are ideas best sampled in small doses à la Rent. The reason is simple: This is a bleak outing populated with sad people who seldom have reason to celebrate life, and on the rare occasions they do Davis's mournful folk-bluegrass music keeps any positivity temporary. This isn't a musical, this is group therapy for clinical depressives.

Robert (Annette O'Toole) is central, of course—he lives in Toccoa, Georgia, and is slowly dying from cancer in the most ironic of possible body parts: the ovaries he never had surgically removed (believing that gender exists strictly in the heart and head). Lola (Jeff McCarthy) is big and burly, and hasn't progressed as far as Robert due to her unwillingness to take estrogen; she's also haunted by memories of the prom she never got to attend in high school. They're friends with two other female-to-male transsexuals: Maxwell (Jeffrey Kuhn), who's pondering his final operation and has begun dating the vivacious used-to-be-a-man Cori (Natalie Joy Johnson), and Cas (Todd Cerveris), who was left seriously scarred by a botched breast-removal operation but who has finally found some happiness with the brash Stephanie (Robin Skye), the only always-been-a-woman in the group. Robert's parents and Maxwell's dad, all three disapproving, make a few token appearances to spread the hate around.

The performances could not be better: O'Toole and McCarthy make a warmly reluctant couple drawn together by their shared adversity, Kuhn and Cerveris drive home Maxwell and Cas's individual demons with sympathetic flair, and Johnson is thoroughly sexy and saucy as Cori. The set, too, designed by James J. Fenton, is a winner: a homespun recreation of a country house's front yard and porch, a fairy tale–like realm where anything good can theoretically happen at any moment. The four members of the onstage band (Allison Briner, Lizzie Hagstedt, David M. Lutken, and Joel Waggoner) are gifted as actors as well, and play some crucial smaller roles that round out the main sextet's interlocking stories.

But because you're forced to focus on all of them at once, and because the only instances of hope presented are incidental, this quickly becomes an unpleasant and dispiriting evening. Aside from five brief interludes that delineate the passing of the seasons, every song except one concerns issues of gender identity or the pain derived therefrom, which is a prescription for tedium. Collins and Davis rendering these people in no concrete terms beyond their sex and their sex lives makes them incredibly shallow and self-centered; you don't really know who these people are, so it's impossible to figure out why you should care about them and what makes their agony special enough to sing about.

Great musicals always have some sense of variety: a soaring ballad here or an honest-to-goodness showstopper there to keep the audience involved and energized in whatever the story happens to be. Collins and Davis seem driven by an agenda, to the point that the show can't (and doesn't) end until each character has made his or her specific point within a barely specific song. Because the running time is a solid two hours and 40 minutes, there's a ton of musical filler that unrolls constantly but fulfills no discernible dramatic need. Its relentless, almost stereotypical Southern style make all the songs sound the same, and their utter lack of joy or even simple contentment leaves you dreading rather than anticipating them.

The aforementioned exception occurs in the second act. "I'm With You" is a brief but charming duet for Stephanie and Cas, in which they reassert their love and attraction for each other, regardless of what genitals they have (or don't have). The nimble number, capped by playful turns from Skye and Cerveris, lets us see not just how much the characters singing it love each other but also why. By the time the two bounce out of the number, we feel, for the first and only time, that these are actual human beings more than anonymous archetypes—and that they had real cause to sing and not just mope. The other pairings in Southern Comfort need similar moments of lovability to prevent their liabilities from being as oppressive as they currently are. Without them, their lives are dark and angry enough to drive the most committed teetotaler straight to the sauce that bears this woebegone musical's name.

Southern Comfort
Through October 29
CAP21's Black Box Theatre, 18 West 18th Street
Tickets online and current Performance Schedule: www.cap21.org