Well maybe it just goes to show you. On Sunday afternoon in the Kennedy Center the Cleveland Orchestra and Lorin Maazel could do no wrong. On Monday night, things were much more up and down.

They began with the first symphony oboes, horns and strings that should Mozart wrote, a piece he scored for be played by about 14 to 16 instruments, including the harpsicord. Maazel overloaded it with twice that many players and the sound was thicker than the beautiful clear texture with which Karajan, Leinsdorf, and De-Preist have brought the same kind of music to Washington. And just what did Klaus Roy's program notes mean in suggesting that the harpsichord today "is of course optional except for reasons of stylistic 'purism?'" Such murky hot air. The playing was, with all the instruments, stylish.

What went best of all on Monday was the Barber Violin Concerto, with Daniel Majeske as soloist. Majeske, the orchestra's superb concertmaster, won a tribute from his colleagues as he had on Sunday with his glorious playing in Strauss's "Heldenleben.' The Barber is technically far more demanding. In its most dazzling pages, which are bunched in the finale, Majeske put on a display of which any violinist would be proud.

The music, far too seldom heard, moves from Barber's more introspective, poetic moods to the dazzle of the finale in which soloist and orchestra move together in a fleeting, quick-silver mood that must be flawless if it is to succeed. Majeske had Maazel's and the orchestra's top-drawer assistance, which meant brilliance of an uncommon kind.

Strange, in a way, that the Tchaikovsky "Pathetique" Symphony should have such a hollow shell: All the notes were there along with some raw flubbing here and there and some immense playing now and then. But Maazel, his motor running a touch fast, took the cheap slowdown for about two beats out of his metronomic reading of the scherzo, gave little emotion to the opening movement, and rushed the second. Ah well, you can't have everything.