The program was billed as "All-Mozart" yesterday afternoon at the Kennedy Center, but a strict constructionist might insist that (like a concert series popular in New York and elsewhere) the music was "mostly Mozart."

The non-Mozart element came in parts of the Mozart Requiem, which was completed by his student Franz Sussmayr after the 35-year-old composer's untimely death. Paul Hill alluded to the fact in dedicating yesterday's performance to Pople John Paul, who "was pope for only 34 days and obviously, like Mozart, didn't get to finish his work."

Whether we blame Sussmayr or Mozart's failing health when he wrote it, the Requiem is uneven music; the inferior parts are merely magnificent, while the best are equal to the finest choral music ever written. In both the Requiem and the Solemn Vespers, K. 339, Hill conducted performances fully worthly of the music - particularly impressive in the mastery with which he balanced his large chorus against his small orchestra. Between the two large choral works, pianist Haskell Small gave neat though not exceptional performances of two-well-contrasted rondos: the ever-popular "Turkish" from the Sonata, K. 331 and the pensive A-minor, K. 511.

The Paul Hill Chorale was (as it usually is) rich and beautifully balanced in tone, splendidly precise indiction and dramatically equal to the music's most fiery passages. Among the solo singers, Donna Gulstrand was particularly impressive in the Vespers, Rose Taylor and Allen Crowell in the Requiem.

The generally fine singing of Kristime Ciesinski had a bit more vibrate than Mozart needs, and tenor James McDonald, though tonely excellent, had pitch problems on one or two notes.