Museums exhibits on music tend to feel jarring. A study of sound in a location known for its silence - it's not quite right.

That the silence helped the experience within the National Heritage Museum on Saturday was almost more of a surprise than the quality of the special exhibit. "Gerswhin to Gillespie: Portraits in American Music" focuses on music photography, but the spirit evoked is one that seems sacred, a look back to different times.

Ghostly. The silence suits the sights.

The collection's 50 photographs run the gamet, loosely separated into four rooms of specific subcategories: Champions of American Music, Great American Composers, Legends of American Jazz, and Icons of American Pop. The overall collection is tied together by a predominant - although not exclusive - theme of black and white photography, and the shift from one section to another feels natural, continuous but marked by small signs noting each change.

Fans of American music's historical twists and turns will find delight in seeing the musicmakers whose names often stood above musical revues. George Gershwin, for instance, sits at a piano, studiously hunched over music with a hand-rolled cigarette dangling from his lip. Cole Porter leans toward the camera, hands folded with the intensely sad gaze that belied many of his most well-known songs. Jim Morrison kneels behind a television, framed by empty closet walls and unused hangers.

But it is the jazz section that draws the strongest gasps. Predominantly a collection of Herman Leonard images, the photographed subjects jump out in lines shockingly crisp are clear. Louis Armstrong's eyes bulge in an intense closeup, complete with spittle.

They are images that capture sound's creation -- but deserve silence. The only way it would feel fitting to take in music while looking at a portrait of Sonny Stitt would be if the jazz saxophonist were able to be in the room, wailing away on his instrument.

Without that, any other sound would serve as a pale substitution - almost an insult.

"Gershwin to Gillespie: Portraits in American Music" is on view through Sept. 17 at the National Heritage Museum, Lexington, Ma. The exhibit is free and open to the public.