There is a certain resemblance between a stage set up for a magic show and stage set for some contemporary music concerts. There is all that intriguing and somewhat threatening apparatuus, black boxes and interestingly shaped things on stands.

All of these were in evidence in ever-changing arrangements last night at the Corcoran Gallery, where the Contemporary Music Forum now makes its home and where they performed the third in this season's series of monthly concerts.

As usual, the program featured new (or almost new) music, skillfully performed and attended to with rapt concentration by the small audience.

It was a well-structured porgram, with works composed with a sense of humor placed as welcome buffers among the fiercely serious ones (this can be important in a concert of this kind). And topping the evening off, there was Russell Peck's "Automobile," a super spoof that begins rather like grim George Crumb and then metamorphosises into a takeoff of just the sort of music heard earlier in the evening.

Others on the light side were "Essays for Trumpet and Trombone" by Elliott Schwartz, a tour de force of intricate punctuation and coordination played to the hilt by David Flowers and John Marcellus, and "Trois Hemines" by Emerson Myers for trumpet (flowers) and percussion (played by Al Merz) that sounds like one or two-measure snatches of every cliche and cadence you have ever heard from the a jazz combo.

In a more serious vein, Helmut Braunlich's "Duo for Violin and Trombone," had its premiere with Braunlich playing the violin. The piece is Hindemithian in concept, with its clear structure and stern aspect. Braunlich has balanced well an unlikely ensemble; and although the piece takes too long to make its point, there are very nice passages.

Soprano Kimball Wheeler, who was both artist and clown in the Peck piece, was all artist in Joel Naumann's "Songs of Silence and the Night," and Mrcellus put in a virtusos performance on Ulf Grahn's "Trombone Unannouncement," whose question mark may refer to the fact that, in this place the tombone produce some chords, more or less.