The first-act pastiche songs are much trickier than the amiable but shallow period glosses in a typical backward-looking score like that of "The Drowsy Chaperone."

Album P.O.L.O.V.I.R.U.S., released in 1998, was a fictional compilation of pastiche songs deriding the condition of Polish popular music.

Over all, though, the orchestrations (by Garry Sherman and Luther Henderson), which are presumably true to the originals, are spiced with a 1960's-style electronic edge that in 2005 seems to undercut the natural force of the spiritual pastiche songs.

Follies (1971) was similarly structured, filled with pastiche songs echoing styles of earlier composers.

The production still gleamed with Susan Stroman's crackerjack staging and choreography and with Mr. Brooks's lovably vulgar pastiche songs.

Some of his evocations are explicit - pastiche songs, he calls them.

But the score is dominated by pastiche songs.

Here, as the co-authors of a book laced with pastiche songs by Elise Morris and Jim Ragland, they approach their classical source with the glee and the attention span of a 2-year-old at F.A.O. Schwarz.

Featuring pastiche songs by Michael John LaChiusa, who wrote the show's book with its director, George C. Wolfe, "Wild Party II" is big on letting its decadent characters suffer loudly and aggressively in the spotlight.

Yet he and Warren Carlyle ... just as clearly revel in the richness of the knowing pastiche songs with which Mr. Sondheim evokes the popular music of the prerock era.