The first thing you see upon opening the program book for In My Body, the new cabaret musical about body-related matters, is a full-page topless photo of a woman after a double mastectomy. It's a startling, unconventionally beautiful portrait of survival that puts you in the mood to see something fearless.

But that's not what you get.

Part pep rally, part yoga class, and all cabaret, In My Body, which premiered Wednesday at the Prince Theater, is a series of vignettes -- mostly musical, with not always comic sketches -- that are sung and performed by an able, five-member cross section of humanity (old, young, white, Asian) encompassed by Donnie Hammond, Michael Indeglio, Austin Ku, April Woodall, and Katie Zaffrann. 

They all kept their clothes on. This show is out to be a safe, mostly upbeat exploration of fad diets, fertility clinics, pillow talk, bullying, and any number of issues no doubt more vital for a coming-of-age audience than theatergoers of a certain age who have discussed and pondered such issues at length (often some years ago) and who can wish for fresh insights that half this show doesn't have. 

The songs  (lyrics by Mike Biello, music by Dan Martin) often sought a kind of generic familiarity, perhaps in the interest of delivering earnest messages as cleanly and selflessly as possible. Complex ideas were, at times, successfully distilled in ways that fell easy on the ear. But more often, the music just wanted to give all-purpose buoyancy to issues so personal they could otherwise seem unseemly. 

Most moving is a portrait of advanced age, in which a woman is bidding a fond farewell to her body and the declining life that comes with it. Least moving is a bullying anecdote about a guy who is embarrassed in front of his high school for having big feet (that's traumatic?). Somewhere in between -- and extremely apropos after Tuesday's election -- is an emphatic litany of all the ways the government tries to legislate body-related decisions. 

Some of the script -- written by Kate Cipriano, Melissa Hays, and Lis Kalogris -- hasn't quite settled, with the cast delivering line readings that hit primary colors when secondary ones would be more effective. The staging often made sophisticated use of the Prince's intimate black-box theater, at turns serious and playful, and with occasional audience participation, like hugging yourself. You get the picture.

In My Body, presented by Flying Bulldog Productions. Through Sunday at the Prince Theater. Tickets: $10-$27. Information: 215-422-4580 or www.inmybodythemusical.com.