The worldwide conspiracy against composer P.D.Q. Bach (1807-1742), who has been hailed as "a pimple on the face of music," took on added force in Fairfax County as the Fairfax Choral Society failed to perform P.D.Q.'s sublime "Missa Hilarious," even though it was listed on the written program.

The omission was not entirely the fault of the Society, since Fairfax County Supervisor Audrey Moore had threatened to withhold the group's $2,478 grant unless the Society joined the conspiracy against P.D.Q. Some citizens had complained of sacrilege in this spoof of how some composers set the mass (it is not a spoof of the mass itself). It is widely performed in other communities around the world, and is available on records.

This new setback to P.D.Q., who has been suffering them hither and yon ever since he and his music were cruelly invented by satiricist Peter Schickele, took some of the edge off the Choral Society's retrospective program of the P.D.Q. oeuvre.

The "Missa Hilarious" is a climactic kind of work, you might say, so it was at the end of the P.D.Q. part of the program. The problem, on short notice, for the Society was, "What could compare with it?"

The Mozart Requiem wouldn't do. After all, Mozart didn't finish it, so it might suffer by comparison. And the Mass by P.D.Q.'s poor relation, Johann Sebastian, just goes on and on, you know. So they finally came up with P.D.Q.'s "Liebeslieder Polkas," his vast impovement upon Brahms' "Liebeslieder Waltzes." They are set to poems by Marvell, Herrick, Marlowe, Shakespeare, Suckling and Jonson. The end results owe much to the poets, but the works also bear P.D.Q.'s indelible stamp.

That great P.D.Q. Bach specialist, Bargain Counter Tenor (as against Over the Counter Tenor or Under the Counter Tenor) John Ferrante, appeared to give definitive performances of "Iphigenia in Brooklyn," among other masterpieces.

And bass David Troop was present to play the drunk in that work and the Basso Blotto elsewhere.

Anything, of course, is anticlimactic after P.D.Q.--absolutely anything. So the second part of the three-hour program, in which the chorus (which has a delicate sound that comes from the fact that it is two-thirds women) returned to normal music, seemed pale by comparison. Special note should be taken, though, of counter-tenor Ferrante's winning versions of Carmen's "Habanera" and "Over the Rainbow."