It’s noted that humans generally like melodies that move with what we call stepwise motion. Basically this just means we like melodies that go from one note to a note next to or close to it. We like it when a C note goes to a D note or an E note, but we aren’t crazy about wider leaps like, say, C to an F over an octave away. And we definitely don’t like a barrage of crazy leaps – that has the “cat walking on a piano” sound.

There are exceptions to this rule of course. A lot of jazz and modern classical music does engage in such wild melodic leps. But that music isn’t particularly popular with the public at large—it tends to be thought of as intellectual music. I doubt you could find a single popular song in history that uses many wide melodic leaps in a melody (the possible exception might be a novelty song of some sort, probably about robots.)

Why is this? One could argue that such big leaps are difficult to play. There’s some truth to that. On almost any instrument it’s easier to run up a scale than to leap about the melodic range of an instrument.

But I suspect something else is at work. An argument can be made that early man evolved to find beauty in the sounds he heard around him. And in nature there are very few examples of sounds leaping around melodically. Most animal calls are fairly stepwise (though there are some wild bird calls out there.) The vibrating sounds of wind and waterfalls tend to fluctuate subtly. They sounds of nature are like hills and valleys much more so than sharp cliffs.

Thus I have spoken.