A documentary by Ron Mann. Rated PG

When is a guitar more than just a guitar? Ask any guitarist and you'll get an earful. But if you ask Rick Kelly, luthier nonpareil and proprietor of a long-standing Greenwich Village music shop, he'll demonstrate that it's an opportunity to reclaim big chunks of old New York and turn them into instruments with history built in.

Kelly's not the most charismatic subject, and veteran Canadian docmaker Ron Mann sticks to a literal nuts-and-bolts approach to a straightforward story. But this doesn't matter much, since top six-stringers like Bill Frisell, Wilco's Nels Cline, and Bahamas guitar ace Christine Bougie stop by to play. Other highlights include visits from quirkmeister Marc Ribot, the Roots' Captain Kirk Douglas, and the guitarists from the Sadies, who also provide incidental soundtrack music.

The shop is not just a boys' club anymore. There are enigmatic songs from Eleanor Friedberger and Eszter Balint, known for her work in the films of Jim Jarmusch, a wire-haired presence who's also an occasional guiding spirit here.

In a kind of subplot that bodes well for coming generations, Mann also focuses on white-maned, goth-tatted apprentice Cindy Hulej, who wandered into Kelly's shop looking for work as a decorative artist and stuck around to become a master builder in her own right. At the other end of the age spectrum, the owner's 90-something mother watches the till and does paperwork while swing music emanates from her little radio.

Surpassing everyone else's lifetime is recovered wood from Manhattan landmarks, stacked in a back room for special orders. Kelly's bench knows one electric-guitar format best: the Fender Telecaster. But within that classic design he allows many tones and textures. A key through-line for the movie follows a thick plank saved from a fire at McSorley's Old Ale House, established 1854, as it gets gradually transformed into an intoxicant of a different sort. Long may it twang.