Unlike football -- or even rock concerts -- an all-star production of chamber music is a high-risk undertaking. If there are flares of temperament, clashes of personality, efforts to hog the spotlight, the music suffers terrible damage -- and obvious too, because the texture of the music is so transparent, the coordination of the players so precise and intimate.

But the all-star approach to chamber music worked superbly on Aug. 30, 1969, at London's South Bank Music Festival, when five of the world's top young musicians joined in a performance of Schubert's "Trout" Quintet: pianist Daniel Barenboim; cellist Jacqueline Du Pre; conductor Zubin Mehta (playing the double bass); violinist Itzhak Perlman and violinist Pinchas Zuckerman (playing viola for this occasion).

The performance was videotaped and will be shown at 2 p.m. tomorrow on Channel 26. It is an excellent reading of a much-loved piece of music, as well as a unique event. This group never performed together before or after, and now it is too late to hope for an encore, because Jacqueline Du Pre was stricken with multiple sclerosis in 1973. The videotape catches her in top form and playing among friends in the true spirit of chamber music. The fact that her friends are all superb musicians makes the occasion even more memorable.

Before the performance, producerdirector Christopher Nupen introduces the musicians in a series of vignettes: Perlman playing (exquisitely) "Rock-a-bye Baby" to his infant son; Zuckerman shopping for a viola; Mehta's double bass coming down the conveyor belt from his airliner.

A relaxed, lighthearted rehearsal scene follows, with Perlman supplying most of the comic relief, playing an impromptu jazz variation of the last movement of Mendelssohn's violin concerto, rattling off "The Flight of the Bumblebee" on the cello and fingering a few bars of Tchaikovsky's Violin Concerto while Mehta handles the bow.

In the close-ups during the performance of Schubert's easy-going music, Perlman looks the most constantly ecstatic, Barenboim businesslike, and Mehta (who had not played the instrument in years) rather grimly determined.