Televised coverage of a live musical performance is a tricky situation at best. The lights, the cables and the camera crews, outfitted in harnesses and kneepads, jockeying for the best shots, are distracting to both performers and listeners. Television crews should never be allowed at a musical show. . .

Well, almost never.

Saturday night at Constitution Hall, the antics of the video wizards proved to be a welcome diversion from the music of fluegelhornist Chuck Mangione. Backed by his quartet and the Special Olympics Concert Orchestra, Mangione presented his watered-down version of jazz to a respectful, if somewhat somnolent, crowd.

Mangione specialized in formulas. Mildly funky rhythms, quasi-bluesy chord patterns and flowing melody lines were insinuated into most of his songs. The result -- from the chunky up-tempo "Fun and Games" to the lush "Land of Make Believe" -- was music that was predictable and demanded little more than superficial attention from the listeners.

This approach extended to Mangione's performance. He hopped and twittered about the stage like a pixie, but he and his musicians seemed to be incapable of infusing any intensity or emotion into their playing.

This laziness contrasted with the enthusiasm of the young members of the Special Olympics Concert Orchestra. They were consistently tight and energetic, and their sound luxuriously sonorous. Mangione, on the other hand, was merely a snore.