"There's no cause for alarm," announced first voilinist Robert Mann at the Coolidge auditorium Friday night before the Juilliard String Quartet and pianist Gilbert Kalish played even a note, in what turned out to be a curious mix of highly skilled and very sloppy performances. "We're just changing the order of the program. First the Irving Fine work, then the Beethoven."

Mann was wrong. Had he been sitting in the audience, he might have heard a delicate-voiced concertgoer whisper, "What in the world became of the Haydn?" The Haydn "Frog Quartet" was originally scheduled last night, but Beethoven's "Sonata in G Major for Violin and Piano" was substituted for the Haydn (in time for the printing of the programs). Fortunately, for those who object to change, the group stayed with Antonin Dvorak's Piano Quintet in A Major.

And just when the audience was reconciling itself to a Beethoven with out the full quartet, conventional tastes had to regroup for a 20th-centrury broadside: Irving Fine's String Quartet. The Fine is actually a magnificent piece of music, but it has to be listened to and appreciated under its own terms -- not an easy task for an audience originally set up for a Beethoven sonata.

Fine composed his quartet in 1952 while he was attempting to fuse his dissonant style with a more tonal style. While the quartet is scored without key signature (a technical guarantee that you can't easily hum or whistle Fine's work), profound melodic effects will result from a disciplined, thoughful interpretation of the work.

Last night the Juilliard Quartet offered such an interpretation. Each player dealt attentively with the work's subtle musical challenges by sustaining long notes and by meticulously manipulating abrupt changes in meter. The Fine quartet, consisting of a spare two movements, ended in a delightfully eccentric whimper.

None of this could have prepared the audience for what became last night's second (and actual) "cause for alarm." Robert Mann faltered conspicuously in the Beethoven. He missed notes, played out of tune and had to depend on the skill of pianist Kalish to bail him out during unison scale passages.

Fortunately, Mann's better playing returned when the entire quartet and pianist Kalish ended with an exciting, vigorously rhythmic Dvorak.