President Boris Yeltsin made a rare appearance in public Wednesday evening at a gala concert at Moscow's Conservatory. At least, he was there for the start of a performance by the Russian cellist Mstislav Rostropovich and Seiji Ozawa, the Boston Symphony's conductor.

By intermission, he was gone.As Russia's new prime minister, Yevgeny Primakov, struggled to patch together a coalition Cabinet last week, Yeltsin's involvement in the affairs of his crisis-ridden country has provided the background noise, audible enough but increasingly distant.

News agencies report his telephone conversations with world leaders and his decrees on ministerial appointments. But Primakov, the artful diplomat, is clearly making the choices that will define Russia's future course as he sifts through opposing political factions in the difficult search for consensus.

How Yeltsin will figure into that consensus is no longer relevant: His views on Russia's economic policies have been washed over by events that have left him isolated and humbled.

For the first time in a career that capitalized on conflicts, Yeltsin backed away from a certain showdown with the parliamentary opposition over the nomination of Viktor Chernomyrdin as prime minister. In Russia's play-for-keeps politics, a compromise - in this case, the nomination of Primakov - carries with it the faint aroma of defeat.

Several analysts still caution against ruling Yeltsin out of the picture entirely, noting that as long as he still has power he will try to wield it, if for no other reason than to ensure his survival in office. Few who know the president expect him to leave of his own free will.