I once had a friend in an experimental jazz group. When asked what instrument he played, he replied, "It's not that kind of band."
That's the vibe behind the answer to our Weird Animal Question of the Week. People have varying ideas about what music is and, it turns out, some animals do too.
Our question comes via Facebook from Victoria Lawrence, whose eight-month-old son Atticus seems to bounce to a beat. She wrote: "It made me wonder: How easy is it to understand music and at what capacity do other animals understand it ...?"
Basically, how animals react to tunes "depends on what we mean by music," says Charles Snowdon, a psychologist at the University of Wisconsin-Madison who studies animal behavior.
Human music—which is made for our ears—has "positive effects on dogs, elephants, and chimpanzees, and negative or no effects on gibbons, baboons, horses, and lambs," he said.
A better way to study music's impact on animals, Snowdon has discovered, is to create tunes tailored to a specific species.
Enter Music for Cats, the team's latest project. Created by University of Maryland composer David Teie, these songs are meant for felines, whose vocalizations have more sliding qualities and pitch changes than do human speech or music.
The tempos for their meow mix includes purring and the sucking sound of kittens nursing. (See "What Do Cats Think About Us? You May Be Surprised.")
Listen to one of the two cat songs from Music for Cats.
The kitty ditties, cat ballads, and feline airs—as the various tunes are called—aren't just cat sounds. They're "actual music that has themes, repetitions, and variations," Snowdon notes.
But are they music to cat ears? In recent experiments, Snowdon and Megan Savage—now a Ph.D. student at the University of Binghamton, in New York—visited the homes of 47 pet cats and played four sound samples in each home: two classical music clips and two "cat songs."
The pets responded most positively to these custom cat compositions by approaching or rubbing up against the speaker more quickly than when they heard the other songs, according to the study, published in February in the journal Applied Animal Behavior.
Such cat music may have the benefit of calming stressed shelter cats or pet kitties left home alone, Snowdon notes.
Before there was Music for Cats, there was Monkey Music.
In previous experiments with captive cotton-headed tamarins, a type of rare South American primate, Harvard and MIT scientists discovered the animals ignored human music, and preferred silence to Mozart.
But Snowdon's team wasn't sure that dissing Mozart meant dissing music altogether.
"What we realized is the vocalizations of these monkeys are three octaves higher than human vocalization or music would be," Snowdon says. The tempo of tamarin calls was also much faster than human speech. (See "Why Did Humans Invent Music?")
So he called upon Teie, who composed music inspired by the sounds of both agitated and content tamarins.
In experiments, tamarins remained nonplussed by human music, but reacted to the moods of the music composed to suit their own frequency and tempo, according to the research, which was published in 2009.
For instance, tamarins that heard music with agitated sounds displayed more symptoms of anxiety, while monkeys that heard content sounds ate more and stayed put—both signs of being calm.
Listen to a clip of happy monkey music.
They've Got the Beat
Whether a species can keep a beat is another animal altogether.
Entrainment—the "ability to hear the beat and to use your body to match it"—is a cinch for people, who do this over a wide range of tempos, says Patricia Gray, director of BioMusic at the University of North Carolina, Greensboro.
In nonhuman animals, entraining to a small range of different tempos has been shown in Ai the chimp, Snowball the cockatoo, Ronan the sea lion, and Kuni the bonobo. (Related: "Alex the Parrot and Snowball the Cockatoo Show That Birds Can Dance.")
Gray and her colleague Edward Large, a psychologist at the University of Connecticut, have given captive bonobos drums that are ergonomically designed for the apes.
In experiments, the drumming bonobos can match the beat of a human drummer when the music is in their preferred tempo range, Gray said.
Perhaps future generations will rock out to bonobo bassists and cool cat deejays—after all, they already know how to scratch.