Daniel Barenboim has invaded New York. Within a few weeks, the chronic overachiever from Argentina, Israel and Germany (in that order) will conduct Tristan und Isolde at the Met, play a piano recital in the opera house (the first of its kind since Vladimir Horowitz's big gig in 1983), lead a concert at the United Nations and celebrate Eliott Carter's centenary at Carnegie Hall. And there he was on Sunday, exploring chamber music with a few friends at Weill Recital Hall.

Weill, with a capacity of 268, is an elegant room upstairs in the Carnegie Hall annex. It normally hosts modest events demanding minimal fanfare. But this event was hardly modest. Barenboim and a fellow overachiever, James Levine, played duets on separate keyboards. The divos devoted half of their brief encounter to Schubert's Grand Duo , opus 140, half to Brahms' Liebeslieder-Walzer .