This is cool. "Boil the Frog" is a 2012 web app by Paul Lamere that creates a "seamless playlist between any two artists."
Boil the Frog lets you create a playlist of songs that gradually takes you from one music style to another. It's like the proverbial frog in the pot of water. If you heat up the pot slowly enough, the frog will never notice that he's being made into a stew and jump out of the pot. With a Boil the frog playlist you can do the same, but with music. You can generate a playlist that will take the listener from one style of music to the other, without the listener ever noticing that they are being made into a stew.
It's kind of like that game "Six Degrees of Kevin Bacon" but for connecting musical styles.
You can give it a try and learn how it works here.