[TEXT OMITTED FROM SOURCE] terday's audience at the opening concert at the National Institutes of Health to go around to the back door. But once they got inside Masur Auditorium, what they heard was worth the trip.

There the New York Soloists, under the musical direction of Melvin Kaplan, played and sang Monteverdi and Vivaldi in a way that proved again the one-time supremacy of Venice in the world of music. Three Vivaldi concertos - for oboe, flute, and piccolo - provided a framework within which Monteverdi was heard in madrigals, musical scherzos, and canzonets. That Monteverdi placed his superb if brief opera, "The Combat of Tancred and Clorinda," in one of his books of madrigals in no way diminishes its high dramatic effect.

The singing was by soprano Susan Belling, tenor Charles Bressler, and bass Raymond Murcell.It could not have been more expert. Bressler's voice, in particular, was as beautiful and expressive as it has ever been heard.

While the eight instrumentalists were all distinguished, and never more so than in the utter charm with which they played pizzicato refrains in "Dolci miei sospiri," the solos by Kaplan (oboe), Solum (flute-piccolo) and Kwalwasser (violin) were outstanding.

Monteverdi's two styles - he called them first and second - were strikingly illustrated with the early unaccompanied canzonets and the imaginative polyphony of the later works. Kaplan's informal verbal program notes added an appreciated touch.