DENVER (AP) — It’s often said music is the universal language of humanity. Now a 12-year-old Houston boy is putting that to the test among an unlikely audience — man’s best friend.

Yuvi Agarwal started playing keyboard when he was 4 and several years ago noticed his playing soothed his family’s restless golden doodle, Bozo. He grew curious if it also could help stressed homeless animals.

With help from his parents, who both have backgrounds in marketing, he founded the nonprofit Wild Tunes in 2023 to recruit musicians to play in animal shelters. So far he has enlisted about 100 volunteer musicians and singers of all ages and abilities to perform at nine shelters in Houston, New Jersey and Denver.

“You don’t have to understand the lyrics to enjoy the music. Just enjoy the melody, the harmony and the rhythms. So it transcends linguistic barriers, and even it can just transcend species,” Agarwal said recently after playing hits like The Beatles’ “Hey Jude” and Ed Sheeran’s “Perfect” on his portable keyboard at the Denver Animal Shelter.

Agarwal, who was playing for an elderly miniature poodle named Pituca — Spanish slang sometimes used to describe a snob — said many of his four-legged listeners, which include cats, become excited when he enters their kennel. But after a few minutes of playing, they calm down. Some even go to sleep.

He remembers a rescue dog named Penelope that refused to come out of her enclosure in Houston to be fed.

“Within a short period of me playing, she went from not even coming out of her kennel to licking me all over my face and nibbling my ears,” Agarwal said.

A few stalls down from where he was jamming on his keyboard at the Denver shelter, volunteer Sarah McDonner played Mozart and Bach on her flute for Max, a 1-year-old stray boxer that tilted his head when she hit the high notes.

“The animals having that human interaction in a positive way, I think, gives them something to look forward to, something that is different throughout their day,” said McDonner, a professional musician who met Argawal in Houston.

She helped bring the program to Colorado after moving to Denver a few months ago. “I think it’s very important to give them something different from what they’re used to in their little tiny cages … and makes them more adoptable in the long run,” McDonner said.

While the effect of music on humans has been studied extensively, its role in animal behavior remains murky.

Several studies suggest that classical music generally has a calming influence on dogs in stressful environments like kennels, shelters and veterinary clinics. But some researchers warn there is not enough data to support the claim.

“We always want these really simplistic answers. So we want to say that music calms animals, for example, and I think that it’s much more nuanced than that,” said Lori Kogan, a self-described “dog-person” who chairs the human-animal interaction section of the American Psychological Association. “There’s a lot more research that needs to happen before I think that we can unequivocally say that music is a great thing for animals.”

Kogan, a professor and researcher at Colorado State University, has studied for more than two decades how animals and humans get along. Research involving the effect of music on dogs often produces mixed results, she said, because there are so many variables: the setting; the volume, type and tempo of the music and the breed of the dog and its previous exposure to music.

She suggests a case-by-case approach to introducing music to animals.

“If you play music for your pet, and they seem to like it and they appear calmer, then I think we can say that that’s a positive thing, that you’re providing some level of enrichment for that pet. … I would encourage people to give it a try and to see how their pets respond,” she said.

For Agarwal, his firsthand experience at shelters is undeniable evidence that music helps comfort stressed animals, and he plans to grow Wild Tunes into a nationwide program. The volunteers get something out of it, too, he said.

“You get a really great way to practice your instrument or sing in front of a nonjudgmental audience, which can boost your confidence,” he said.