Postcards on Parade, the new musical in previews at the York Theatre Company in Manhattan has been returned to sender: The York canceled the problematic show April 20.

Despite previews April 14-19 (after a delay of several days), artistic director James Morgan shut down the four-actor tuner after the evening performance April 19. A letter is being sent to the York's 600 subscribers admitting that the new show, by lyricist-librettist Kenward Elmslie and composer Steven Taylor, "isn't working" and is "not ready."

Subscribers to the York's three-show mainstage season are being credited with the next season's first mainstage show, which has yet to be announced.

The cancellation is a high-profile setback for the not-for-profit York, noted for its presentations of intimate musicals in its space at The Theatre at St. Peter's, in the Citicorp Building at 54th Street and Lexington Ave.

Insiders said the surreal show, about a postcard collector who deals with a personal loss by seeing postcards come to life, is a development blunder for the York, which has had the conceptual script and demo in hand since 1999, presumably enough time to make a decision about the work's stageworthiness before rehearsals. The show's scuttling comes in the same season as York's biggest box office hit, Jolson and Co., which has been mentioned for a future commercial production. The York's recent revue of John Latouche's work, Taking a Chance on Love, was supported by generous grants and lured in musical theatre buffs curious about late lyricist Latouche, who was once called "the preface to Sondheim." Taking a Chance on Love has been preserved in a cast recording expected to be released on the Original Cast label.

Also this season, the York got national media attention with a starry concert revival of 70, Girls, 70, in the troupe's popular Musicals in Mufti series. The Mufti presentation of Wright and Forrest's Kean was considered by insiders to be an artistic setback.

*

Postcards on Parade was supposed to begin previews April 11, but that first performance was bumped to April 14.

Clayton Phillips, a Hal Prince protégé who staged Kiss of the Spider Woman abroad, was director.

Poet Elmslie previously penned a Broadway musical stage version of The Grass Harp, drawing from Truman Capote's story. In the final years of John Latouche's life, Elmslie was the lyricist's "significant other," according to a Playbill bio. He has also penned libretti for six operas.

The Postcards on Parade cast was to feature Jennifer Allen (Cats, Little Me), John Hillner (Footloose), Mark Lotito (The Most Happy Fella) and Randy Redd (Parade, By Jeeves).

According to the Playbill, songs in the new tuner included "It's a Good Life," "Busy Correspondence Card," "P-P-P-Pain," "King Kong Stan," "Paradise of Beauty," "One Day at a Time," "Take Me Away, Roy Rogers."

Andy Blankenbuehler, a dancer featured prominently in Fosse and Saturday Night Fever, was choreographer. Designers were Morgan (set), Mary Jo Dondlinger (lighting), Lynn Bowling (costumes) and Michael Clark (projections). Musical direction and arrangements were by Jack Aaronson.

Official opening was to be April 27, with performances continuing to May 21.

For information, call (212) 239-6200.

-- By Kenneth Jones