Picture this scene:

One of history's supreme pianists seats himself at a Steinway in Israel's Jerusalem Theater. He has recently turned 88. He appears amazingly fit. But his eyesight is beginning to fail. And he realizes that this is likely to be the last time he will play Beethoven's "Emperor" Concerto.

The pianist, of course, is Arthur Rubinstein. The date is April 15, 1975. And the stunning hour of drama in the concert hall that unfolds will be shown tonight on WETA (Channel 26) at 8 p.m.

The concert is both magnificent Beethoven and a poignant valediction by the man whose career, among the extraordinary pianistic peers of his time, soared the highest.

To say that Rachmaninoff, or Horowitz, or Rubinstein, or anyone, was the greatest pianist is to make a glib and arbitrary distinction. But as Alexander Schneider, who conducts a fine performance with the Jerusalem Symphony in this broadcast, observes in an interview, Rubinstein was "unique."

Rubinstein played more different kinds of music more musically than anyone else. Like other giants of the century--his friend Stravinsky, for instance--Rubinstein eluded stereotypes. He has been hailed as the last of the Romantics, but it was also he who changed the course of Chopin playing by cutting out Romantic excess. And, as we hear in this "Emperor," his Beethoven had more of the classical than the Sturm und Drang to it.

From the opening bars of the "Emperor," with those mighty ascending arpeggios and tricky runs punctuated with their anything-but-delicate trills, the qualities that were inimitably Rubinstein's are captured in the tape of this concert. Those runs are as uncannily even, both tonally and digitally, as they were four decades earlier. No pianist produced beautiful sound and steady articulation more consistently and subtly than Rubinstein.

This is not as Olympian an "Emperor" as Serkin's, or one as charged with nervous tension as Schnabel's. Rubinstein never played the "Emperor" that way. Clarity and purity and poise are the strengths here.

As usual with Rubinstein's "Emperor," it is in the ecstatic understatement of the central slow movement that he is most eloquent. The slow tempo and simple line free him to lavish his seemingly inexhaustible resources of color and nuance on the music. Listen to the subtlety of the accents of his entrances, made perfectly explicit but so gentle they don't begin to threaten the smoothness of the line; this sequence is an object lesson in lyric phrasing. And there is also the voicing of the chords in the piano's second subject, soft but crystal clear in their tonal luster--reflecting an unsurpassed mastery of pedaling.

All of this is recorded in a superb visual frame. The keyboard shots are grand, but as in any film of Rubinstein the most memorable shots are of that mournful face, its penetrating eyes with those heavy lids just barely open--looking all the more like a figure out of El Greco as the years etched their lines. (And if you look closely you will see the equally photogenic visage of Golda Meir out in the audience).

The effects of age (he would retire within a year) mar the playing only once, during some octave runs in the first movement's development section when he loses his place for a measure or two.

Rubinstein died last winter, at 95. As Schneider observes, "God bless him. He will be remembered forever."

He will certainly never be forgotten as long as this deeply moving performance of the "Emperor" survives.