January 8, 2010
Thanks to all the iTunes users who've turned on Genius, iTunes is able to continually build and refine a sophisticated map of musical affinities which it can then use to help you notice other music you might like, and to automatically create playlists of songs in your library that go well together. To turn Genius on, select it in the lefthand column in the iTunes window and follow the prompts. When you're done you'll find two new buttons at the bottom right, one that hides and shows a Genius Sidebar with recommendations, and one you use to create Genius playlists.
You create Genius playlists by selecting a song in your library as the starting point and clicking the Genius button. A list of 25 songs will appear in the iTunes window, accompanied by three buttons on the right side of the Based On: bar at the top of the list. One lets you up the song total to 50, 75 or 100, another (Refresh) fetches a new mix of possibilities, and Save Playlist saves the contents to your Genius section under the name of the song you used to create it. You can save as many Genius playlists in that section as you like. (Note: if the song you picked as the starter is one Genius doesn't have enough affinity information for, it will ask you to pick another.)
Genius Mixes take the automation one step further, using the Genius map to create up to 12 different mixes from the artists and genres it finds in your library. If you select Genius Mixes (in the Genius section in the left column) and then point at each "album cover" in turn, you'll see the mix's name and some of the artists it includes at the bottom of the window -- "Alt. Singer/Songwriter Mix, Based on Leonard Cohen, Imogen Heap, Tom Waits, & others," for instance. The overall result feels like your own personal different radio stations you know will continually surprise you with music you like.