How did music begin? Did our early ancestors first start by beating things together to create rhythm, or use their voices to sing? What types of instruments did they use? Has music always been important in human society, and if so, why? These are some of the questions explored in a recent Hypothesis and Theory article published in Frontiers in Sociology. The answers reveal that the story of music is, in many ways, the story of humans.

So, what is music? This is difficult to answer, as everyone has their own idea. "Sound that conveys emotion," is what Jeremy Montagu, of the University of Oxford and author of the article, describes as his. A mother humming or crooning to calm her baby would probably count as music, using this definition, and this simple music probably predated speech.

But where do we draw the line between music and speech? You might think that rhythm, pattern and controlling pitch are important in music, but these things can also apply when someone recites a sonnet or speaks with heightened emotion. Montagu concludes that "each of us in our own way can say 'Yes, this is music', and 'No, that is speech'."

So, when did our ancestors begin making music? If we take singing, then controlling pitch is important. Scientists have studied the fossilized skulls and jaws of early apes, to see if they were able to vocalize and control pitch. About a million years ago, the common ancestor of Neanderthals and modern humans had the vocal anatomy to "sing" like us, but it's impossible to know if they did.

Another important component of music is rhythm. Our early ancestors may have created rhythmic music by clapping their hands. This may be linked to the earliest musical instruments, when somebody realized that smacking stones or sticks together doesn't hurt your hands as much. Many of these instruments are likely to have been made from soft materials like wood or reeds, and so haven't survived. What have survived are bone pipes. Some of the earliest ever found are made from swan and vulture wing bones and are between 39,000 and 43,000 years old. Other ancient instruments have been found in surprising places. For example, there is evidence that people struck stalactites or "rock gongs" in caves dating from 12,000 years ago, with the caves themselves acting as resonators for the sound.

So, we know that music is old, and may have been with us from when humans first evolved. But why did it arise and why has it persisted? There are many possible functions for music. One is dancing. It is unknown if the first dancers created a musical accompaniment, or if music led to people moving rhythmically. Another obvious reason for music is entertainment, which can be personal or communal. Music can also be used for communication, often over large distances, using instruments such as drums or horns. Yet another reason for music is ritual, and virtually every religion uses music.

However, the major reason that music arose and persists may be that it brings people together. "Music leads to bonding, such as bonding between mother and child or bonding between groups," explains Montagu. "Music keeps workers happy when doing repetitive and otherwise boring work, and helps everyone to move together, increasing the force of their work. Dancing or singing together before a hunt or warfare binds participants into a cohesive group." He concludes: "It has even been suggested that music, in causing such bonding, created not only the family but society itself, bringing individuals together who might otherwise have led solitary lives."