Taste Rewind asks you pick a few artists that you like, and tries to find similar artists for every decade, from the '60s to the aughts (with a 1920s playlist thrown in for good measure). You can then hear a sampling from each playlist, or add them to your Spotify collection for later listening.
Admittedly, Taste Rewind is a bit limited in its current state, as the playlists seem to only draw from a small list of sources for each chosen artist. Also, as someone who hasn't used Spotify much (I was an Rdio subscriber until recently), I had trouble getting the site to offer up music I liked in its artist picker, even after adding more artists to my library and playing some songs.
That may explain why Spotify isn't making a big deal out of Taste Rewind, with no sort of announcement around it. The site was only spotted by VentureBeat after a Spotify developer posted about it on Facebook.
Still, there's nothing stopping anyone from trying it out, both on desktop and mobile browsers.
The story behind the story: While Taste Rewind is a clever concept on its own, it also showcases Spotify's developer tools, which allow other apps and services to tap into Spotify in smart ways. For instance, there's a site thatturns Spotify songs into music video playlists, and an integration with RunKeeper that offers workout playlists as you exercise. Spotify has also teamed up with Uber to let passengers listen to their playlists during a ride. As Spotify faces new competition from Apple Music, interesting uses of its developer tools could be one way to stand out.