I’ve read the first couple chapters of This is Your Brain on Music: The Science of a Human Obsession. I don’t know if I’ll finish it, because I don’t seem to be in the mood for long non-fiction books at the moment. But there are some really interesting things. First, there is a definitive answer to the “if a tree falls in the woods…” question. The tree causes air and soil molecules to vibrate for sure. But for that to qualify as “sound”, it has to be detected by ears and transmitted to a brain, where it becomes sound. Squirrel ears can qualify, so the brain doesn’t happen to be human. In fact, scientists have put electrodes in animal brains and confirmed that they react to sound exactly as our brains do. So it’s interesting me to that we are born wired to understand music at a neural level – this is an instinct actually much more fundamental than language.

There’s some more interesting stuff. The reason a violin sounds different from a flute or a human voice has mostly to do with overtones – a note is not just a single pitch but many mathematically related pitches where the strength varies between pitches. (Some people say the violin is the most beautiful instrument because it is most like the human voice. I say this is an insult to violins.) There is also the “attack”, which is the percussive noise made when sound first starts on a given instrument, which is chaotic for a short period of time before stabilizing. Then there is reverberation or echo of the space the instrument happens to be in (as I was musing about pipe organs recently, you could think of the space as part of the instrument since it is so fundamental to the sound). Pipe organs are particularly interesting because they give the organist control over which overtones are sounded at various strengths. Digital synthesizers are intended to do exactly this, but I think anyone with well-functioning ears can still detect the difference between a synthetic sound and one produced by physical instruments. Then again, as most of the music we hear these days is recorded and played back, we are probably losing a lot of nuance of what the instruments sound like at the same time the synthesizing technology is continuing to improve.