THERE'S SOMETHING wonderful, almost magical, about those grand old showhouses of the 1920s and '30s. With their ornate interiors and awesome, almost cathedral-like auditoriums, they turned the relatively simple routine of moviegoing into an event.

More often than not, there was magic on the screen as well _ colorful, tune-filled musicals, John Wayne westerns, frothy "drawing room" comedies.

The miniature crackerboxes we call theaters today just don't compare.

But some of that magic is returning to one of Salt Lake's most ornate theaters _ the former balcony of the historic Utah Theater at 148 S. Main.

Before the theater was "twinned" several years ago by what was then Intermountain Theaters, the stately Utah was _ along with the Capitol and Promised Valley Playhouse (then the Lyric) _ among the finest examples of those lavish old vaudeville houses.

The best place to sit was the balcony, especially the loges. Those always had the premium price because of the excellent sightlines. Downstairs may have been closer to the concession stand, but the balcony, with its dress circle and steeply-raked seating, was someplace special.

Now, part of the magic of sitting in the Utah's balcony _ or what used to be the balcony _ is back, thanks to Salt Lake Repertory Theatre (City Rep).

When City Rep leased the Utah several months ago from Cineplex Odeon/Plitt Theaters, what they got, in showbiz jargon, was "a two-fer" _ two theaters for the price of one. There's a proscenium style "mainstage" theater downstairs, and City Rep's new "Family Theater" in space that used to be the Utah's "penthouse" theater upstairs.

The newly renovated space - which still features much of the ornate decor of its prime - will seat 400 around a Shakespearean style "thrust" stage. City Rep's artistic director Joanne M. Parker plans to utilize the stage for a season of children's theater.

From day one, when City Rep moved in last year, Parker had envisioned the intimate, elegant former balcony as a showcase for family theater, while the main stage would be used for large-scale musicals and other productions.

Theater patrons will have their first opportunity in many months to go back into the upstairs section of the Utah Theater next week when City Rep's Family Theater makes its formal debut with the premiere of a musical adaptation of "The Pumpkin Giant," a Halloween tale written in 1892 by Mary Eleanor Wilkins.

Director Joanne Parker and collaborator Reuben C. Fox dramatized the work for the stage.

Basically, it's the story of a villainous Pumpkin Giant who terrorizes a mythical kingdom by devouring chubby little boys and girls. One potential victim is the king's daughter, Princess Adrianna Diana.

Set in medieval times, Parker and Fox utilize mimes to portray exaggerated caricatures of the emotions and reactions of various characters.

The cast includes Tommy Barron, Ginger Bunnell, Owen Richardson, J. D. Sullivan, Raelynn Potts, Perry S. Coe, Becky Burnett and Erick Cloward, along with Jim Perryman, Michael Fox, Barclay Tucker, Courtney Ladd Bello, Emily Rosemarie Parker, Nigel James, Marini Myers, Summer Sutherland, Sarah Brown, Sanders Sharp, Justin B. Smith, Amy Short, Lindsay Rasmussen, Portia Early, Clair Evans, Jill Thomas, Ann Eliza Gates, Karen Anne Webb, Timothy N. Turner, Shellie Waters, Rebecca Gibbs and Lily Crawford.

Ruben C. Fox, artistic director for Hansen Planetarium, is working with Parker to create a soundtrack of music and special effects for the background. Earlier, they collaborated on a stage adaptation of "The Snow Queen," which won first place in the American Theatre Association for Youth original play competition in 1986.

Assisting with the show are Owen Richardson, City Rep's resident set designer, and Donna Johnson, costumes.

Evening performances of "The Pumpkin Giant" will be at 7:30 p.m. on Oct. 10, 14-15, 17, 21-22 and 24 and Nov. 12, 14, 18-19, with matinees at 2 p.m. on Oct. 29 and Nov. 5. Single tickets are $6.50 for adults and $4.75 for children.

Season tickets for all five "Family Theatre" productions are available at $20 for children and $25 for adults. For further information or reservations, contact the City Rep box office at 532-6000.