As the trio rehearsed the new opera, singing and spinning, co-composer Saskia Lane kept reminding them of their future audience — tiny, young and, at any moment, crawling across the stage.

"Get lower," Lane told one of the performers, sinking into a deep squat.

"Your 'whee' needs to be a little quieter," she gently noted.

"It's good to be centered," she said, drawing the trio back, "but there might be a baby there, who knows?"

Minnesota Opera is presenting a new opera for babies. For their parents, too. But children 2 and younger are the focus of "Nooma," a playful, musical world filled with parachutes, butterflies and breathing.

Twin Cities newborns and infants can experience the work during performances Thursday through Saturday in a rehearsal hall at Ordway Center as part of the Flint Hills Family Festival.

The 25-minute piece, co-commissioned by Minnesota Opera, premiered in April at Carnegie Hall in New York. Next, it pops up at the San Francisco Opera.

"When you say 'opera for babies,' everyone in my world laughs," said Lane, a Brooklyn-based bassist and composer. "It's not funny, actually. It's serious.

"We're trying to make something with a high artistic standard … something beautiful that works for this age — and for the grown-ups in the room."

In Europe and, increasingly, the United States, opera companies are ushering the youngest, tiniest possible attendees into an art form known for graying audiences. If they're trying to attract people under 30 with ticket discounts and happy hours, they're tempting the under-3 crowd with pillow seating and stroller valet. Dress code? Onesies welcome.

"It's really gotten me to think about how we engage our audiences," said Jamie Andrews, Minnesota Opera's chief learning officer. "Honestly, it's a learning curve for me. It's a new age for us to work with."

A few years back, he flew to California to see the San Francisco Opera's first foray into opera for babies — the U.S. premiere of "Up in the Mountains," by a Norwegian ensemble. He saw video of the piece beforehand, and "didn't really have an opinion about it," he said, shaking his head.

But sitting under a tent with performers and infants, he understood. "I changed my perspective 180 degrees. When you see and experience the energy and bond that's created with this roomful of babies who are following the story, it's pretty amazing."

Andrews returned to Minnesota with a mission: "We have to do a baby opera. We have to do this."

Baby operas are short. "Young babies can't take more than 25, 30 minutes," Lane said.

They often take place not on main stages but in intimate side rooms. "The temperature in the room is important," she said. "Carnegie was freezing, and these kids are on the floor. We were adamant that they turn it up."

They leave space for the babies — physically and musically. "We learned that there are a lot of offerings being made by babies," Lane said. "And it's really great if you can accept the offer, respond and engage."

Zoë Palmer, who wrote the libretto for this piece, said she places less emphasis on drama and focuses on creating a safe, magical space for exchange between the performers and the tiny audience members.

"In this way, we like to think of them as our co-creators, and I usually write them into the work," she said. "This also helps our performers interrogate their role, which is actually a more nuanced set of interactions than straightforward performance."

In "Nooma" — the title is a play on the ancient Greek word "pneuma," meaning breath and spirit — Palmer's text uses onomatopoeia and other sounds rooted in research around babies' early language development. The three characters are named Nimoo Nimoo, Ayo and Yoya — no tricky consonants in the bunch. They spin and dance and play peekaboo. Audience members hold onto a parachute while the trio hold hands, singing: "Breathe out, breathe in." Children may stay after the opera to play for a bit.

Research shows that the breathing patterns of a 1-day-old change depending on whether they're listening to Stravinsky or Mozart, according to a 2014 TED Talk by Dimitri Christakis, director of the Center for Child Health, Behavior and Development at Seattle Children's Research Institute. "Even at one day of life," he noted, "there's a discernible physiological reaction to what babies are hearing."

"Nooma" is an opera, so every word is sung. Babies mimic and respond. They sing and coo and, sometimes, cry.

Before a recent rehearsal, Lane talked about how hard it is to rehearse without babies afoot. She suggested that the performers — Rebecca Blackwell, Sara Sawyer and Ivory Doublette — gather a few infants for a rehearsal or two, as "they'll make some discoveries."

"The babies are the missing cast," Lane said. "It's as if you've been practicing something and the lead hasn't shown up yet."

Jenna Ross • 612-673-7168 • @ByJenna

One of the performers in “Nooma” interacted with a young audience member during its premiere at Carnegie Hall last month. “We like to think of them as our co-creators,” said the opera’s librettist, Zoë Palmer. (The Minnesota Star Tribune)