A wedding ring. An Agnes B. scarf. One black Gucci pump. The lost items eulogized in the musical Gone Missing tend to be expensive, stylish, andabove allsorely missed. Their absence sends their owners into fits of desperation, even operatic anguishthese are reactions we typically associate with lost love, not lost accessories. A peculiar theatrical experience, Gone Missing bills itself as a "documentary musical," and it largely delivers what it promises. The six members of the Civilians acting company interviewed more than 30 New Yorkers and assembled a familiar panorama of urban eccentricity: a jaded cop, a talky Jewish dowager, a Korean grocer, a Pakistani cabbie, and a cell-phone-addicted yuppie fashionista. This bustling mosaic vibrates with energy and intelligence, even if the overall dramatic picture remains curiously devoid of shape. The talented actors perform their impersonations with admirable restraint, though certain vignettes tend to go on too long (the show feels extended at an intermission-less 75 minutes). Periodically, the cast breaks out into a strange robotic dance or performs a song in a foreign language-these too-infrequent non sequiturs point to a slightly loonier and more experimental musical that Gone Missing aspires to, but can never quite achieve.