This is probably something that happened to you. You have carefully created the perfect playlist for your mood and you love every single song that is in there. But, you only listen to that playlist for about 20 minutes so you don’t hear every song in your playlist. You are listening to your music every day and after a few listening sessions you start to notice something weird. In that playlist, there are some songs you haven’t heard in weeks! How can that possibly happen if you’ve been listening to that playlist on shuffle for a month? Turns out, streaming platforms don’t give you a true random shuffle feature, and it is also not something you should be interested in.
Humans can’t comprehend true randomness
The biggest problem with randomness is that our perception of true randomness is not necessarily what true randomness actually is. Let’s illustrate that with an example. In the list below there are three strings of text, each with 2 A’s, 2 B’s and 2 C’s. Which one of these look the most random to you?
If you chose option 1 or 2, you are wrong. Each of the strings are equally random. Just because one string has the equivalent characters grouped together, it doesn’t mean that it is less random.
Why you also don’t want true randomness
Up until 2014, this randomness was how Spotify used to shuffle songs in a playlist. But eventually, people started to complain that they thought that this shuffle feature was not random enough. If you replace the letters in the randomness example above with some artists’ names you can see why. With true randomness, the songs of a specific artist tend to clump together. People see this as not truly random and will complain about it. This can of course be solved by not having the same artist twice in a playlist, but this is not how people create their playlists.
How does the shuffle algorithm actually work?
Spotify has actually been very transparent about their shuffling algorithm in the past. The algorithm essentially works by clustering the individual artists and spreading them out evenly. Granted that this article was from 2014, it is safe to say that this algorithm has changed a bit since then, but the core principles of this algorithm still remains. Spotify probably takes your listening history into account when shuffling your playlist because they want to keep you listening long as possible. Given that we tend to listen to the same set of songs for a long time, this seems to be very likely. But, that will most likely remain a secret.
To illustrate this system I’ve done a little experiment myself. I have shuffled the playlist I listen to the most often 3 times and visualized the first 10 songs in the picture below. The full playlist is 30 songs long. What is the most interesting is that 3 of the 30 songs appear 3 times in the first 10 songs and 6 of the 30 songs appear 2 times in the first 10 songs. Also, none of the artists are repeated twice in a row, except for a song where the main artist is a featured artist on the next song. This reinforces the idea that in Spotify’s shuffle, artists are spread out as much as possible.
So what do you think? Is the shuffle algorithm of Spotify justified? Leave a comment below!