Dunster House calls Duet "Two plays for music," apparently indicating that the nature of Arthur Kopit's dramas makes a special provision for more music than the average play allows; i.e., more than a few atmospheric preludes. Well, there is more music than that, but anyone who expects a quasi-operatic commentary on the action will be disappointed. Victor Ziskin and Thomas Beveridge (particularly Mr. Beveridge) have worked rather in the manner of the film composer: a few bars to concentrate the atmosphere during a silence, music for the dances and circus performances Mr. Kopit has thoughtfully provided; low-volume impressionistic reveries while somebody on the stage soliloquizes.

In general, these procedures worked very well. Mr. Beveridge was wisely discreet in composing "Sing to Me Through Open Windows": his few touches set off the material of the drama without getting in its way. Unfortunately, the purely musical effects were partially obscured because no one saw fit to adjust the loudspeaker volume above the mezzo-piano level.

Music formed a greater part of the fabric of Aubade, a play which might conceivably have been composed as an oversize operatic scena. Mr. Ziskin wrote two longish preludes, a good-sized postlude, and supported the heroine enthusiastically during her moments of crisis. The style ranged from jagged dissonance (which was not too successful) to rapid-fire splashes of delicious French harmony, which Mr. Ziskin handles with great verve.