What Do Computers ‘Think’ of Pop Music?


When Stevie Wonder wrote “Music is a world within itself, with a language we all understand,” the word “all” meant “all people.” But that was in 1976. With the rapid advancement of technology, music is gradually becoming a language that can also be understood by computers, so that computers can have their own “opinion” about music and musical styles.

Music is a fairly complex type of data that introduces a challenge for computing machines. Identifying the beat, chords, or musical instruments can provide a computer with some information about a musical piece, but the concept of music is greater than merely its describable components. Even the exact same song can be produced or performed in various different ways, and each version can make a different impact or trigger different emotions. So to allow a computer to “listen,” we used as much information as possible about each song, including pieces of information that do not necessarily have a formal definition, but carry information about the music. That was done by first converting the audio into a two-dimensional representation called “spectrogram,” basically turning a music analysis problem into an image analysis problem. For instance, the following image is a visualization of Bobby Bland’s “dreamer”. The horizontal axis is time, the vertical axis is frequency, and the brightness is the volume, so the image actually contains all information about that song.

Then, we computed from each spectrogram almost 3000 numerical values that reflect its texture, shapes, edges, fractals, statistics, polynomial decomposition, and more. These 3000 values were then analyzed by applying algorithms that can identify repetitive patterns typical to a certain group of songs, but are not so typical to other groups of musical pieces. The shared patterns between different musical styles were quantified and visualized.

For instance, if we take several different —> Read More