`WHO ARE Brahms?" asks an old joke making light of the composer's changing musical idiom. But if the composer had always written music like his three sonatas for violin and piano, the witticism would never have gained currency. Far removed from the composer's youthful sturm und drang, these autumnal pieces represent a tempered and philosophical old master.

Be that as it may, it is difficult to imagine that Brahms would have approved of the overly pensive performance of the sonata in G major, Op. 78, with which violinist Alan Gilbert '89 and pianist Ben Loeb '88-'89 opened their otherwise fine recital last Saturday night in Paine Hall.

Their opening Vivace ma non troppo sounded suspiciously like an Andante, and even as the last two movements unfolded at more appropriate tempos, one had the sense that the two musicians were trying too hard not to make mistakes.

If this recital of all three Brahms sonatas started with a relative whimper, it was to improve continually and finally end with a bang. After their nerves settled down, the musicians together set about their business with a genuine musicality that betrayed no romantic excesses.

The sonata in A major, Op. 100, is Brahms at his most intimate and endearing, and here Gilbert was in top form. Throughout the first movement, marked Allegro amabile, you could see him opening up to the audience, both musically and physically.

In place of his antiseptic tone in Op. 78, he started to evince a wonderfully flexible and expressive array of sounds that never abandoned him.

A couple of botched passages by pianist Loeb couldn't come close to spoiling the rapt beauty of the Andante tranquillo and Allegretto grazioso. Here one heard a surprisingly fine rapport between pianist and violinist, though the balance was too far slanted toward the violin. Loeb seemed too close to the edge of the keys, and his sound was not as well defined as it might have been.

ASIT turned out, he was saving the best for last, as the D minor sonata, Op. 108, the most virtuosic of the bunch, was the evening's most polished performance, with an near-ideal balance between the players.

Gilbert shaped the pastoralsounding second movement, marked Adagio, with exquisite care, and in the last two movements Loeb played octave and chordal passages with gusto: he had obviously prepared well. The audience, which filled only one-third of the hall, applauded heartily, and the ovation was well deserved.

All that said, one may well wonder at the wisdom of programming concerts as one might "program" a recording. Brahms's late music is beautiful and profound, but it is also, from an audience's standpoint, exhausting to listen to in long stretches.

One would have liked to hear, for variety, at least some Beethoven, or better yet, some impressionist music or contemporary works. Still, one looks forward to more student recitals sponsored by the Music Department.