Credit: The Granger Collection, New York

Detail of the autograph of the motet, 'God is Our Refuge,' written by Wolfgang Amadeus Mozart at age 9, 1765.

What makes a sound music? Many animal sounds can stir the emotions of human listeners--but so can trains and rainfall. Music involves both the aesthetic response to sound and the intent to elicit these responses. Humans use music to express emotions, inspire emotions in others and create shared feelings among groups. Animal "songs" more likely just announce a territorial claim or a readiness to mate. Still, who can say for sure what a bird experiences when it sings?

© AMNH / Rod Mickens

What Animals Can Do

Many animal calls and songs resemble music. But is it really music when a cricket chirps, or just instinctive behavior with no artistic intent? Most such sounds are genetically programmed, with no true creativity or self-expression behind them. But some animal songs are not built in--they are learned and modified after birth. We still don't know the exact function of all the songs that animals produce.

What Humans Can Do

Besides expressing emotions, music has important social functions. Music can help bond the members of a group through common experience or instill an event or ritual with meaning or emotion. Multiple human musicians, all playing different parts, can create a single piece of music linked by a rhythmic beat. We use tones on defined scales, which may be united by harmony. Humans play a variety of musical instruments and pair music with other art forms such as dance. Other species do some of these things, but combining them all is unique to humans.

© Michael & Patricia Fogden/Minden Pictures

Granular Poison-dart frog (Dendrobates granulifer), male calling, rain forest, Costa Rica

Born to Croak

In many frog species, males gather at night and sing in choruses to attract females. The frogs are not expressing something invented or learned; within each species each frog's call is very similar, largely predetermined before birth by its genes.

Photo: Nigel J. Dennis/Gallo Images/Getty Images

Carmine Bee-eaters (Merops nubicus) & White-fronted Bee-eaters (Merops bullockoides), Okavango Delta, Botswana

Seductive Singers

Birds often sing to attract mates. In places where females preferred lengthy songs, male songs evolved to become longer, as birds with longer songs had more offspring and passed on that trait.

A Bird That Drums

Humans play a wide variety of instruments, while animals generally create sounds with their bodies alone. But there are exceptions. The palm cockatoo, for instance, is known to beat hollow logs with sticks to make loud drumming sounds.

Creating Art

For humans, music is more than just spontaneous expression. Humans can think of a piece of music as having an existence distinct from the maker.

Animals In Action

Many animal calls are instinctive. Some animals songs, however, are not innate, but are invented and constantly altered, and some can be extremely complex. The humpback whales, for instance, organize notes into phrases, phrases into themes, themes into songs, and songs into song cycles.