Matt Mullenweg listens to a single song on repeat when he needs to get in “the zone.” This is fascinating to me, as I am a Spotify user fueled by chaos. I have always been a little spastic about my Spotify playlists, creating new lists for each month based on my musical whims at the moment. The idea of restricting myself to only a few songs at a time is absolutely absurd. I had to try it. I created a playlist of three songs that I’ve already been playing quite a bit:

Armed with my newly crowned “Focus” playlist, I got to work late at night when my brain was starting to fall asleep. I sat down to some frustrating programming tasks, put my playlist on repeat and began my experiment.

It worked! As I ramped up into my work, I immediately found the flow much faster than normal. I focused on the lyrics on the first pass, a bit less on the second pass, and by the third pass I was barely aware of the background noise. It was fantastic. Even the slower beats of “The Masterplan” weren’t breaking me out of an energetic flow. I cranked through everything I’d set out for myself without a second thought.

Why does it work? Surely there’s something in the human psyche that makes this work for me just as well as it does for Matt. What is it? I needed to do some research.

Arkansas psychologist Elizabeth Hellmuth Margulis wrote book called On Repeat: How Music Plays the Mind that tangentially delves into this question.

Musical repetition gets us mentally imagining or singing through the bit we expect to come next… A sense of shared subjectivity with the music can arise. In descriptions of their most intense experiences of music, people often talk about a sense that the boundary between the music and themselves has dissolved.

Okay, that helps us out. The more we listen to music on repeat, we tend to dissolve into it. That’s extremely useful for creative work, when tuning out the monkey mind is of utmost importance.

There’s a psychological principle at work here called the Mere Exposure Theory. It states that we like something the more we’re exposed to it; we like the familiar. W.R. Kunst-Wilson and R.B. Zajonc demonstrated this can happen with the most mundane of objects by flashing octagons at experimental patients and finding that they liked octagons much more after the subliminal stimulus. Though we eventually get sick of songs, it’s quite easy to swap them out for others in the playlist after we hit our threshold.

I think we have our answer. Repetition of anything makes us like the thing even more, while repetition of music specifically helps us sink into a groove. Perfect for improving our mood and ramping up our productivity at the same time.