The Washington Chamber Orchestra opened its season last night in Ford's Theatre with a benefit concert, which was also the first in the orchestra's new subscription series.

Haydn's Symphony No. 7, the "Midi," which should have been a brilliant curtain raiser, lacked the bounce, the incisive attack and, in the slow movement, the kind of suave stylish line that give this music real joy. Neither Alvin Lunde, the conductor, nor the players seemed geared up for it.

Things improved with the G Major Concerto of Mozart. Concertmaster Timothy Baker understands the style and the kind of tone that make this the most celestial of all the Mozart violin concertos. In the second movement, the muted strings took on something of the sound that had been missing up to that point, and the flutes, replacing the oboes, provided real radiance. Had Baker taken his time at the outset of the movement as he did in the later restatements of its opening theme, the entire passage would have been admirable.

The evening closed with the great G Minor Symphony, No. 40. It is a hard fact of life that this music, particularly in a theater where every note is clearly projected, requires something like perfection from every player. If there were episodes of beauty, there were also too many passages in which intonation and balance were missing.

Perhaps as the orchestra moves into its new season, it will smooth out the present roughnesses.