Homo musicis: Why humans make music

Daniel Levitin. This is Your Brain on Music (2006) Levitin was in the music business in LA for many years, but discovered a yen for understanding what it was all about. So he became a neurologist, believing that understanding how the brain works when we make or respond to music would explain it all. It doesn’t, but it comes close.
     Music is species-specific behaviour: only humans make music.We could label oursleves homo musicis. Other animals use sounds for communication and for courtship displays, but none, as far as we can tell, play around with sound-sequences like we do. Not even whales.
     Every known culture and society has music. The three features of music are rhythm, melody, and harmony. What’s interesting is how we perceive them. Rhythm is built on sequences of strong and weak beats. We recognise the same rhythm whether played fast or slow. Melody is a sequence of intervals, not notes: we recognise the same melody whether played with higher or lower notes. Harmony in the sense of timbre is omni-present: human voices and all musical instruments generate different combinations of overtones in addition to the main tone. Think of chords as deliberately created and controlled overtone groups. Then a melody becomes a sequence of chords combined with a rhythm. By the way, a melody can be played with different rhythms. And in every culture, music and dance are connected. You can’t have one without the other. (The Western habit of suppressing movement while listening to a performance is a relatively short-lived aberration.)
     Levitin sees two puzzles: First, how do we perceive and produce music? Second, how come music is such an apparently necessary part of human experience? Even people who are tone-deaf experience music as more or less pleasurable. Neurology provides some of the answers. Every part of the brain is involved when we make or listen to music. The cerebellum controls repetitive movements. The cortex plans them, and generates expectations. The limbic system supplies both the memory and the emotions. (It’s unclear just how many melodies we can recognise, for most of us it’s in the hundreds.) The auditory system decodes the complex wave-forms of the sounds of music, and delivers the results to other areas of the brain that recognise melody, rhythm, harmony, and the words of a song. Music is intimately connected with movement and language.
     We use music to build community. Although we can make it a solitary pursuit, it is first and foremost a collective one. We sing together, we dance together, we make music in groups. We prefer the music of our ingroup. Music is part of our courtship behaviour. It persists in our memories after dementia has destroyed almost every other part of our selves. A fragment of a song will trigger memories, and the emotions that accompany them. Music is such a pervasive part of our individual and collective experience that we take it for granted, and hardly realise how much it shapes our lives.
     As you can see, it’s complicated. Levitin has become a premier researcher in the neurology of music. Every result raises new questions. This book is now 14 years old, and recent work on questions of consciousness, mental health, the role of emotions, dementia, etc, have superseded some of his insights, but on the whole I think it’s an excellent introduction to music as a human endeavour. Levitin is an academic, so he tends to pile on the details, but that’s the only flaw in a very good book. Recommended. ***