Here’s What Carly Rae Jepsen and Cannibal Corpse Have in Common

January 4, 2013 | Andy Cush

Echo Nest developer and all-around music-hacker extraordinaire Paul Lamere’s latest creation, entitled Boil the Frog, uses algorithms to create a smooth, gradual playlist from one artist to another, no matter the genre. That means we can finally find the six degrees of separation from Taylor Swift to Tchaikovsky, Lady Gaga to Madonna, or Nazi black metallers Der Stürmer to Das Racist.

How does it work? Take it away, Paul:

To create this app,  I use  The Echo Nest artist similarity info to build an artist similarity graph of about 100,000 of the most popular artists. Each artist in the graph is connected to it’s most similar neighbors according to the Echo Nest artist similarity algorithm.

To create a new playlist between two artists, the graph is used to find the path that connects the two artists. The path isn’t necessarily the shortest path through the graph. Instead, priority is given to paths that travel through artists of similar popularity. If you start and end with popular artists, you are more likely to find a path that takes you though other popular artists, and if you start with a long-tail artist you will likely find a path through other long-tail artists. Without this popularity bias many routes between popular artists would venture into back alleys that no music fan should dare to tread.

Once the path of artists is found, we need to select the best songs for the playlist. To do this, we pick a well-known song for each artist that minimizes the difference in energy between this song, the previous song and the next song.   Once we have selected the best songs, we build a playlist using Rdio’s nifty web api.

So how do you get from Carly Rae to Cannibal Corpse? I won’t spoil it for you, but I will say its first jump is absolutely perfect and a testament how well this things. From Jepsen’s saccharine mall-pop to the punk-tinged saccharine mall-pop of Avril Lavigne. Check out the rest here.