Everything on last night's National Symphony program was new to the orchestra, from the bouncy Rossini overture to "La Scala di Seta" at the beginning to the Fifth Symphony of Dvorak at the end.

Nothing, however, was as new as the two concertos in between, which received their world premieres. First came the Symphony No. 36, for solo flute and orchestra, which is Opus 312 by Alan Hovhaness. Commissioned by the Discount Book Shop for Jean-Pierre Rampal, the music took on a radiant glow from the effulgent glow of his playing. But for over 35 minutes it wandered aimlessly through groves of elementary harmony in which the common triad mingled with exotic sevenths and nints to no purpose.

It ended up sounding as if Little Mary Sunshine was trying to find her way out of the Casbah by singing "Mighty Like a Rose." More than half the time Rampal had nothing to do but to stand there waiting for his next entrance so that he could again play like an angel lost in a kindergarten. What a shame. The orchestra played as beautifully as he.

Things were certainly different in the ensuing concerto for double bassoon by Gunther Schuller, precisely as Rostropovich had planned in placing concertos for high and low-range winds next to each other.

With every apt compositional device in the way of rhythmic variety, harmonic color and melodic invention. Schuller surrounded Lewis Lipnick's contrabassoon with a wealth of sounds that never lacked an inventive idea.

The concerto, commissioned by the National Symphony, is a taxing assignment, and one that may, with today's instrument, still be beyond reasonable reach, in spite of Lipnick's authoritative playing. For example, there were times when the solo instrument simply could not be distinguished from its friendly colleagues. Perhaps adjustments in the making of the orchestra's lowest wind voice could give it greater carrying power in its middle and upper range.

The writing for both soloist and ensemble was of great skill and imagination, with fascinating passages for everyone. The audience did not miss the humor with which the scherzo quickly passes, or the work involved in Lipnick's body English and disciplined breathing. Both he and Rampal were warmly welcomed at the end of each concerto, the audience standing for the flutist.

The Dvorak symphony at the close of the long program opened with a welcome combination of characteristic orchestral brio and suitably rich sounds. The program is being repeated tonight and Thursday night.