THERE WERE striking contrasts apparent in last Friday night's three concertos at Kirkland House--contrasts in tone, color, ensemble, period, and most obviously in performance style. Gerry Moshell led a diverse program of Bach, de Falla, and Tchaikovsky. As a conductor, he has proved again that one need not be limited to a specialty to produce creditable performances. He was aided in varying degrees by the soloists.

A balky harpsichord nearly destroyed the Bach Fifth Brandenburg at the start of the evening. A sticking action, hampered by the intense heat of a packed JCR, combined with a number of broken plectra to render the instrument nearly useless. Hugh Wolff, the harpsichordist, somehow managed to play through the 70-bar cadenza at the end of the first movement, in the process inadvertently producing a number of truly bizarre harmonies. Wolff appeared remarkably calm and demonstrated a fine technique when not obscured by the instrument's problems. Given that the Bach was the first of two programs that same evening, the wisest decision would have been to abandon the harpsichord, switching to piano for the rest of the Bach as well as the entire de Falla concerto.

The other two members of the concertino, flutist Barbara Jacobson and violinist Ronan Lefkowitz, were excellent in different ways. Jacobson was a model of reserve, barely moving as she played with a rich tone in the modern flute's lower registers. Lefkowitz, far more demonstrative, played the occasionally showy violin part with a good deal of flair. He communicates a sense of awareness of the music, suggesting he has thought about it and knows exactly the sound and effect he wishes to project.

Moshell wisely dispensed with conducting the slow movement which had original but tasteful ornamentation. Once the string orchestra caught up with the last movement tempo, the piece finished solidly. The overall effect was a unified one, despite the sometimes grave difficulties with the harpsichord.

ROBERT PORTNEY, violin soloist in the Tchaikovsky, was not helpful to the ensemble. He appeared lost in indifference when not tuning his instrument (during several orchestral passages) or playing solo. His technique is impressive and certainly of professional caliber. His very mastery might cover up for the cavalier attitude he held toward an audience he apparently felt was not up to New York concert standards. Coming to a dead stop in the middle of the first movement cadenza, Portney explained that it was hot (more than obvious to everyone in the room) and that he wished to tune the violin. When finished, he continued the cadenza from his stopping point. As one amused orchestral member put it later, it was the first-ever four-movement Tchaikovsky violin concerto.

Yet the playing was extremely good. Portney does have a staggering technique. If his hair-flicking, soul-stirring mannerisms were toned down--they look ridiculously out of place for such a young man--he would have far more to offer as a performer.

The rarely-heard de Falla Harpsichord Concerto was done in the middle of the program. It has a bright, attractive third movement where seemingly by accident a melody found its way into the oboe part. The movement is atypical of de Falla and slightly reminiscent of Poulenc. The first and second movements are far more percussive with frequent marcato chordal passages. Moshell and Wolff, their earlier roles reversed, were here soloist and conductor. The breakdown of the harpsichord precluded any fair judgment of the piece or its performance.

The Bach and Tchaikovsky were good choices for the personnel. The level of playing from soloists and orchestra was consistently high. The program was strictly oriented to its soloists and the concertos projected their abilities as well as their personalities with uncanny accuracy.