It all depends on definitions.
If sound is a mechanical wave that is a periodic compression and rarefaction of pressure that travels through a medium like a solid, liquid, gas or plasma a sound is indeed made. An observer is unnecessary. But most of us restrict sound to a range of frequencies that can be detected (usually by us) and are given meaning in the brain. We are surrounded by an extremely complex field of these waves of mechanical energy that are interacting with each other and their surroundings. Our ears turn these pressure waves into electrical impulses that are conducted to our brain which manages to make sense of all of this. We hear crashing trees, crickets chirping in the evening, the distant bark of a dog and music. A neuroscientist might use a definition of sound that is information processed by and listened to by our brains. With this definition we need an observer and a brain.
I’ve been thinking a lot about music today. I’m a terrible musician, but that doesn’t diminish my enjoyment and the question of perception is fascinating. Perception is central to digital music compression1, but and you find your self wading into territory that is still being explored.
Our silvermitt ferret Telemna loved music. Some how we gave her a little toy piano and found she loved to make sounds by striking its keys. A week or so saw her progress from random notes to strings that were more musical. Soon she was only playing what we called music. We got her an eight key piano and she quickly figured out how to make what we heard as music on it. I would play an unresolved chord and she would run up and play the "right" note. An astonishing talent.
Telemna was fascinated by any music in the house and loved loud Ethel Merman types who could belt Broadway tunes. She would hear something and later would play up to about eight notes of what she must have liked.
Stephen Pinker of Harvard believes music is an accident of evolution - it serves no purpose, but it is nice to have around. For him it probably only exists in humans. A few years ago I read Daniel Levitin’s delightful This is Your Brain on Music. (If you haven’t read it take a break and order a copy. While you're at it pick up a copy of Musicophilia by Oliver Sacks.) Levitin suggests it is deeper and more important. I sent this video of Telmena working out a tune (pardon the messy room and the low quality Flip video):
his reply: “In your face Stephen Pinker!”
Unlike sound, music is clearly a construct of the brain. A stereo left playing in the woods sans audience is not producing music. Some of us can read sheet music and “hear” it in our heads. Most of us can listen to memories of music and a few can even create new music - starting in our heads, but then translated to something that produces the bits of acoustic energy that make up sound.
The emotional power of music can be enormous. Today I was reminded of this directly. On Friday I will be in a high stress situation and have been reaching out to friends. A very close friend told me she would spend time meditating with some music - specifically some wonderful surf music by the Duo Tones2.
I give an enthusiastic recommendation to the group. Two master guitar players and some amazing performances. She had no way of knowing that I was familiar with them as they are a bit obscure, but she knew enough about me to know what type of music would be appropriate. The choice of music is important as it covers a terrifically wide emotional range. The niches filled by recommenders and DJs are important and the gift of a playlist can be rich and important.
Music is a component of how I handle stress. As an undergrad in Pasadena I rarely made it to the beach, but somehow I relaxed with pieces ranging from surfer music to piano trios. My technique was to spend the day before an intense event (say a major test) by listening to music and taking long walks or bike rides rather than last minute cramming. The matching of music to the task was important and surfer music works well for quantum field theory and particle physics and the Duo Tones offer the purest performances I've encountered. Why they also are perfect for my current issue is a mystery to me, but she sorted it out and recommended them without any knowledge of my history with the genre. I took a walk in the dark chill of the evening is a sea of swilling colors from performances nearly a decade ago by these masters and as I walked knowing she was doing the same knowing it would support me I was struck by how moving and beautiful this gift of suggestion and action was. I suspect music is a common glue for many of us as we communicate beyond the limits of speech with others.
There is so many things to yet learn about music. An anthropologist friend and I were looking into this a decade ago. She observed that all known cultures in the world had percussive music and all but a tiny handful had singing. We thought it would be fascinating to learn enough to compile a book On Music that would be similar in Sontag’s On Photography. Of course we were far to naive on our part. Even so there were a series of real epiphanies and I'll probably write about a few as time goes on.3
So find a nice chair, sit down and carefully listen to a favorite piece or three of music today. If you are lucky perhaps you will make some new discoveries as I managed with Wipeout tonight.
1 If you are worried about compressing CD quality music using Apple's AAC codec anything over 256 kilobits per second is overkill and if you are over forty anything over 160 is overkill - trust me on that one ... The subject of what accurate audio reproduction is happens to be a rich subject and CD quality stereo isn't a great match, but is pretty good for most of us.
2 Highly recommended is their acoustic album Surf Music. Their electric work is also amazing, but you also need their purely acoustic music.
3 A good example is that the enjoyment of music often is decoupled with the quality of reproduction. I was in a classic restored Mustang near Cleveland with the head recording engineer from Telarc Records and a seriously good musician from the Oberlin Conservatory. We were talking about where music reproduction might go with sound field reconstruction and dramatically more information than CDs could provide when a favorite Beatles tune came up on the 8 track (gasp! - it was an authentically restored Mustang). The volume came up and the two of them were soon singing along to the music in pure delight. There is something transcendent about the music - even with the awful reproduction in that noisy environment. This taught me home stereos might die if we could only give people good enough music that was always with them. Portable music players with cheap headphones would be good enough.
There were also many cultural learnings. Music does not exist in a vacuum and there is a rich and fascinating interplay of music and culture.