When humanity's ancestors discovered, a million years or so ago, the exquisite pleasure of a hot meal by the fire, they might very well have set the mood with a little night music -- a shimmering cadenza played on a slender bone flute, perhaps, or a hymn to the spirits belted out a cappella.
As researchers conclude in the current issue of the journal Science, the love of music, that unslakable, unshakable, indescribable desire to sing and rejoice, rattle and roll, is not only a universal feature of the human species, found in every society known to anthropology, but is also deeply embedded in multiple structures of the human brain, and is far more ancient than previously suspected.
In fact, what could be called the ''music instinct'' long antedates the human race, and may be as widespread in nature as is a taste for bright colors, musky perfumes and flamboyant courtship displays.
In twin articles that discuss the flourishing field of biomusicology -- the study of the biological basis for the creation and appreciation of music -- researchers present various strings of evidence to show that music-making is at once a primal human enterprise, and an art form with virtuoso performers throughout the animal kingdom.
The researchers discuss recent discoveries in France and Slovenia of musical instruments dating back to 53,000 years ago -- more than twice the age of the famed Lascaux cave paintings or the palm-size ''Venus'' figurines. The instruments are flutes carved of animal bone, and are so sophisticated in their design as to suggest that humans had already been fashioning musical instruments for hundreds of thousands of years. And when Jelle Atema of the Marine Biology Laboratory in Woods Hole, Mass., an author on one of the new reports and an accomplished flutist who studied with the renowned Jean-Pierre Rampal, reconstructed his own versions of the archaic flutes from bits of ancient bone and gave them a blow, he and his collaborators were impressed by their sweetness and versatility.
''What you immediately hear when he plays these flutes is the beauty of their sound,'' said Patricia M. Gray, the lead author on the first of the two Science articles. ''They make pure and rather haunting sounds in very specific scales.
''It didn't have to be this way,'' she added. ''They could have sounded like duck calls.'' Dr. Gray, a professional keyboardist, is the artistic director of the National Musical Arts, the ensemble-in-residence at the National Academy of Sciences, and the head of the academy's Biomusic program, a group of scientists and musicians who, according to their mission statement, ''explore the role of music in all living things.''
The new reports also emphasize that humans hold no copyright on sonic brilliance, and that a number of nonhuman animals produce what can rightly be called music, rather than random drills, trills and cacophony. Recent in-depth analyses of the songs sung by birds and humpback whales show that, even when their vocal apparatus would allow them to do otherwise, the animals converge on the same acoustic and aesthetic choices and abide by the same laws of song composition as those preferred by human musicians, and human ears, everywhere.
For example, male humpback whales, who spend six months of each year doing little else but singing, use rhythms similar to those found in human music, and musical phrases of similar length -- a few seconds. Whales are capable of vocalizing over a range of at least seven octaves, yet they tend to proceed through a song in stepwise lilting musical intervals, rather than careering madly from octave to octave; in other words, they sing in key. They mix percussive and pure tones in a ratio consonant with that heard in much Western symphonic music. They also follow a favorite device of human songsters, the so-called A-B-A form, in which a theme is stated, then elaborated on, and then returned to in slightly modified form.
Perhaps most impressive, humpback songs contain refrains that rhyme. ''This suggests that whales use rhyme in the same way we do: as a mnemonic device to help them remember complex material,'' the researchers write. ''It's very easy to play along with pure, unedited whale songs,'' said Dr. Gray, who has written movements for saxophone, piano and whale. ''They're absolutely comprehensible to us.''
Birds, too, compose songs with the same notes, rhythmic variations, harmonic patterns and pitch relationships as those found in human compositions. The hermit thrush, for example, considered one of the lushest of avian vocalists, sings in the so-called pentatonic scale, in which the octaves are divided into five notes. ''This is a very recognizable and very pleasant scale that is found across many human cultures,'' Dr. Gray said. ''The pentatonic scale is the scale on which the prehistoric flutes are built, and it's also the basis for a lot of rock 'n' roll music today.'' Birds of a feather, it seems, rock together.
The California marsh wren may sing as many as 120 themes in a given jam session, with each theme matched by its immediate neighbor in what is known among musicians as the call-response pattern. Some birds even use instruments: the palm cockatoo of Northern Australia selects a hollow log of a preferred resonance, and then breaks off a twig to use as a drumstick.
''Music is far, far older than our species,'' said Roger Payne, president of the Ocean Alliance in Lincoln, Mass., and a co-author on one of the papers. ''It is tens of millions of years old, and the fact that animals as wildly divergent as whales, humans and birds come out with similar laws for what they compose suggests to me that there are a finite number of musical sounds that will entertain the vertebrate brain.''
Neuroscientists have just begun getting a handle on how the brain perceives and appreciates music, and the results are as yet confusing and somewhat contradictory. On the one hand, Dr. Isabelle Peretz of the University of Montreal and her colleagues have studied patients with lesions in the auditory cortex that impair only their ability to recognize music, while leaving unscathed their power to understand speech, environmental sounds and other acoustic information.
Dr. Peretz's results suggest that the brain has something specifically designed to process music, although the precise location or nature of such a do-re-mi keeper remains unknown.
On the other hand, Dr. Mark Jude Tramo, a neuroscientist at Harvard Medical School, argues in the second Science paper that neuroimaging studies of people performing or listening to music have failed to find a ''music center'' in the brain devoted strictly to music cognition.
All of the neural structures that participate in the musical experience, he argues, are players in other forms of cognition, auditory and otherwise. For example, Dr. Tramo says, a region called the left planum temporale, which is critical for perfect pitch, is also involved in language processing. And though the right hemisphere of the brain traditionally has been considered the ''music hemisphere,'' recent neuroimaging studies from his and other laboratories reveal a more subtle interplay between the left and right halves of the brain in the course of a musical experience.
The left hemisphere seems particularly important for so-called ''fast acoustic'' processing, which would tell a listener whether, say, a note was being bowed on a violin or plucked on a guitar. The right hemisphere takes over in ''slow acoustic'' processing, appreciating the notes following that initial ''attack.'' At which point, if all goes well, the brain cedes control to the body, and the party begins.