Variety could even decrease over time. In fact, there may be a bizarre
example of that happening right now in human song. We can easily explore the
changing amount of variety in songs over the last hundred years because of an
amazing data archive: audio recording. Since the beginning of recorded music,
the sound of human song has changed with each new generation of people.
There's no confusing a 1930s song with a 1940s song, or a 1950s song with a
1960s song. The pattern sticks until roughly the end of the 1980s. It's not
easy to tell whether a song came from 1990 or 2000.
This might sound like an extraordinary claim, but you can test it yourself.
Listen to random clips from the many sources of songs available on the
Internet and don't peek at the year they were produced. You'll discover that
it's harder to date songs from the last two decades than songs from previous
decades. Terry and I are now considering this experiment on a more formal
If you accept that there has been a recent decrease in stylistic variety in
human song, the next question is "Why?" There are plenty of possibilities:
Maybe the Internet makes too much information available, so everyone has the
same influences to absorb—and songs lose flavor and take on a generic
quality. To be more cynical, it could be a sign of cultural decline.
Another explanation, which is the one I suspect, is that the change since the
mid-1980s corresponds with the appearance of digital editing tools for music.
Digital tools are more suggestive about results than previous tools: If you
deviate from the kind of music a digital tool was designed to make, the tool
becomes difficult to use. For instance, it's far more common these days for
music to have a clockwork regular beat. Some of the most widely used music
software becomes awkward and can even produce glitches if you vary the tempo
much while editing. In predigital days, tools also influenced music, but with
not nearly such a sharp edge.
So this is an ironic moment in the history of computer science. We are
beginning to succeed at using computers to analyze data without the
constraints of rigid grammarlike systems. But when we use computers to
create, we are confined to equally rigid 1960s models of how information
should be structured. The hope that language would be like a computer program
has died. Instead, music has changed to become more like a computer program.