The collection of Herman's populist musical theatre tunes, told in the context of fresh relationships within the new conceptual revue, is satisfying its target audience of fans of showtunes. The show was previously announced for an engagement to March 30 only.

Arrangement are by James Followell, and Bobby Peaco is on piano.

Here's how the show is billed: "Showtune weaves together some of Herman's lesser-known riches from Mack and Mabel, Dear World, The Grand Tour, Milk and Honey and A Day in Hollywood, with fresh and surprising turns on the popular standards from the Tony Award-winning musicals Hello Dolly!, Mame and La Cage aux Folles.

The cast includes Sandy Binion, Paul Harman, Russell Arden Koplin, Tom Korbee, Karen Murphy, Bobby Peaco and Martin Vidnovic.

Theatre at Saint Peter's is at 619 Lexington Avenue at 54th Street, lower level of Citicorp Center. Tickets are $65. For information, call (212) 239-6200.