It's Music to These Monkeys' Ears -- and Also Their Hearts

Whales have songs, and so do birds, of course. But does music lift the spirits of a swallow? Do humpbacks hum to make themselves mellow?

Although bird songs and many other animal vocalizations have been the subject of intense scientific study, the effect of music on the moods of creatures other than humans has remained mysterious. If anything, research has suggested that animals are indifferent to human music, whether it's a sonata, a ballad or a rocker.

But a provocative new study, spawned by an unusual partnership between a cellist with the National Symphony Orchestra and a psychologist at the University of Wisconsin at Madison, has provided some of the first evidence that humans are not the only species whose heartstrings are pulled by music.

"We've basically shown for the first time that the components of music that seem to be important in affecting us emotionally are also the same components that affect other species," said Charles T. Snowden, the Wisconsin psychologist who teamed up with David Teie of the National Symphony Orchestra.

Snowden has spent years studying a diminutive species of monkey known as the cotton-top tamarin. These tamarins live in the rainforests of Central and South America and are known for their highly complex and frequent vocalizations.

"They use a lot of sounds in their natural communications system," Snowden said. "They were a natural species to study something like this."

Teie, who also teaches music at the University of Maryland in College Park, contacted Snowden in the hopes of exploring his ideas about the emotional effects of music. He thinks music has roots in the most primitive, earliest sounds to reach our ears, such as a mother's heartbeat.

After studying Snowden's extensive catalogue of recordings of tamarin calls and spending a couple of days in Madison making his own recordings of the primates, Teie set out to compose music tailored to the tamarins.

"My idea was, there's no reason for Barber's 'Adagio for Strings' to bring tears to the eyes of a tamarin," Teie said. "So I made a special kind of music just for them."

Teie modeled his compositions on two types of calls -- one that the monkeys emit as alarms and another that they produce when they are safe and calm. He created two songs designed to be agitating like a heavy-metal song and two designed to be calming like a ballad, using the standard structures of human music but utilizing the rising or falling pitches and durations of sounds in the monkey calls.

After recording the songs with his cello, Teie speeded them up eightfold to match the tempo and frequency of monkey vocalizations.

"They are tiny little creatures, and everything moves very fast when they chirp to each other," Teie said. "So I sped it up eight times so it would make sense to them."