It’s a Monday night at Joslyn Art Museum’s Witherspoon Concert Hall, where a surreal scene worthy of Federico Fellini unfolds. The strange confluence of sights and sounds represents the final preparations before the evening’s dress rehearsal of Gaetano Donizetti’s 1841 opera Maria Padilla, one of three music theater works now showing in Opera Omaha’s Fall Festival.

While carpenters’ electric drills whir away on an unwieldy set piece near the front of the stage, a harpist begins playing behidn them. Soon, violins, horns and percussion instruments are heard over the workmen’s din, as Omaha Symphony Orchestra players gather in force. Other production crew members climb ladders high into the rigging overhead or adjus lights. Stage managers cart spears, pillows, grapes and other props in the wings.

And as if on cue a woman bedecked in a flowing white wedding gown appears like an apparition in a side aisle. She surveys the hubbub, then disapepars. She is one of the costumed actors who pace in and out of the hall as the rehearsal’s 8 p.m. curtain call passes without the set piece having budged. It seems the union crew is having trouble fitting the parts of the large trihedron together.

Rehearsal is already 15 minutes late. A long night lies ahead; the cast and the opera’s conductor and director are anxious because Maria Padilla will make its American premiere only five days later.

Opera Omaha technical director Brady Mittelman had already spent a few all-nighters at the Witherspoon when interviewed a week before Maria’s September 14 opening. Mittelman, who joined the company only 13 weeks ago, has had a baptism-by-fire.

When Carousel closed July 31 he had three weeks of pre-production to call union crews and figure lighting, sound and stage requirements for the Fall Festival, which presents three works in repertory. Then work began on moving an army’s worth of equipment into the Witherspoon and installing it.