Whether all the on-camera fretting and joking about her first big night on Broadway is real or not, Kathie Lee Gifford will face the music Dec. 7, when she steps into the Carol Burnett role in Stephen Sondheim's Putting It Together.

She's not replacing Burnett in the so-called "review" of songs at the Ethel Barrymore Theatre, just playing Tuesday evenings to allow Burnett a couple of days off per week. Burnett, who received the best reviews of the Eric D. Schaeffer-directed musical, which opened Nov. 21, will appear in the holiday-weeks Tuesday shows, however, on Dec. 21 and Dec. 28.

Meanwhile, other Tuesday night shows, typically less populated than other performances, are expected to be full of Gifford fans who watch her syndicated morning TV talk show, "Live With Regis & Kathie Lee." In recent weeks, Gifford and co-host Regis Philbin have been kidding (apparently) about how nervous she is about appearing in the revue.

A spokesman for the show said she will perform the same songs as Burnett and that nothing has been dropped. The sketchy character in the revue is a bitter middle-aged woman whose marriage is chilly due to her husband's wandering eye and their commitments to other projects and people.

Some minor lyric changes are expected for Gifford, but nothing specific could be confirmed. Gifford, a proud Christian, requested "wait a goddamn minute" be changed in the lyric to "Could I Leave You?" (from Follies). The new lyric is said to be, "Wait a f****** minute." While a stranger to Broadway, Gifford is no stranger to show business: She's performed at Rainbow and Stars, has released several albums ("Sentimental," "It's Christmastime") and guest starred on TV programs from "Touched By an Angel" to "Diagnosis Murder." She authored the books, "I Can't Believe I Said That," "Christmas With Kathie Lee" and "Listen to My Heart."

Her co-stars on Tuesdays are John Barrowman, George Hearn, Ruthie Henshall and Bronson Pinchot, who also share the stage with Burnett.

*

Bit by bit, Putting It Together, the "review" of songs by Stephen Sondheim, was meticulously pieced together toward its Broadway opening, Nov. 21.

Previews began Oct. 30 at the Ethel Barrymore Theatre, where the marquee announces the show as a "review," as in career review, not "revue." Nevertheless, Putting It Together is both a conceptual revue and review of Sondheim theatre songs (familiar and un-), placed in the context of a cocktail party in which Carol Burnett raises a glass with fellow partygoers Barrowman, Hearn, Henshall and Pinchot.

During its preview period, "Come Play Wiz Me" from Anyone Can Whistle was dropped to make way for Carol Burnett doing a gender bent rendition of "Everybody Ought to Have a Maid" (with Pinchot) from A Funny Thing Happened on the Way to the Forum..

Sondheim has tweaked some lyrics to make them specific to the world of Putting It Together, in which yearnings and tensions are revealed as the evening progresses. Schaeffer directs, Bob Avian (Miss Saigon) choreographs.

Schaeffer is the rising director who has staged Sondheim's work to acclaim in Washington DC. Avian co-choreographed A Chorus Line and created musical staging for Miss Saigon.

*

Putting It Together (which pulls its title from a song in Sondheim and James Lapine's Sunday in the Park With George) has its roots in a 1992 English production devised by Sondheim and Julia McKenzie. She directed that version at the Old Fire Station, Oxford, England , and Cameron Mackintosh, who nurtured Cats, The Phantom of the Opera, Les Miserables, produced.

The show had its New York City premiere in 1993 at Manhattan Theatre Club, by special arrangement with Mackintosh. Julie Andrews led a McKenzie-directed cast.

Now, Andrews' old pal, Burnett, is in the role of The Wife. The stock characters in the Broadway production are known as The Husband (Hearn), The Younger Man (Barrowman), The Younger Woman (Henshall) and The Observer (Pinchot).

This new production is an extension of an October-December 1998 staging seen at the Mark Taper Forum in Los Angeles. The creative team for the California run was the same, but John McCook played The Husband and Susan Egan (Triumph of Love) was The Younger Woman.

The two-act Putting It Together includes 33 songs and an entr'acte (orchestrated by longtime Sondheim collaborator Jonathan Tunick). Shows represented include The Frogs, A Funny Thing Happened on the Way to the Forum, Anyone Can Whistle, Company, Follies, A Little Night Music, Sweeney Todd, Merrily We Roll Along, Sunday in the Park With George, Into the Woods, Assassins, the film "Dick Tracy" and the unproduced TV musical, "Do You Hear a Waltz?"

Putting Together together are designers Bob Crowley (set and costumes), Howard Harrison (lighting), Andrew Bruce and Mark Menard (sound). Burnett's costume is by Bob Mackie. Wendall K. Harrington provides projections. Paul Raiman is musical director.

*

While best known for her comedy/variety television program, "The Carol Burnett Show," Burnett was beloved by Broadway audiences for her starring role in Once Upon a Mattress. She left Broadway for many years after appearing in the Hollywood-satire musical, Fade Out- Fade In, but returned in 1995, in the Ken Ludwig comedy, Moon Over Buffalo.

Barrowman's credits include London's Beauty and the Beast and The Fix, Broadway's Sunset Boulevard, among others. On Broadway, Hearn appeared in The Diary of Anne Frank, Sweeney Todd, La Cage aux Folles and Sunset Boulevard and more. British Henshall is an alum of the Chicago revival in New York and London. Pinchot is best known for the role of Balki in the popular TV series, "Perfect Strangers."

For ticket information, call (212) 239-6200.

-- By Kenneth Jones