The Genius Mixes in iTunes are nice: they group related tracks in convenient playlists without any intervention on your part. But they do have their flaws: you can’t see which tracks are in them, so you never know what’s coming next. Also, if you have a small-ish library and you listen to the same Mix for a long time, songs can start to repeat, as though they’ve been duplicated. But Hints reader Plan K came up with an ingenious way to get the benefits of a Genius Mix without those two problems.
For starters, create a new playlist (File -> New Playlist or Command-N). For the sake of explanation, let’s call it Select Genius. Next, select iTunes DJ in sidebar. (If it’s not there, open the General tab in iTunes’ Preferences and select iTunes DJ in the Show section.) At the bottom of the iTunes DJ window, select the Genius Mix you want from the Source drop-down. Click on Settings and choose to show 100 upcoming songs; while you’re there, select Play Higher Rated Songs More Often to make it more likely you’ll hear songs you like (assuming you’re diligent about rating your tracks).
Now here’s the clever way Plan K gets rid of duplicates: Select then drag the first track in the iTunes DJ playlist to the Select Genius playlist. Then go back to iTunes DJ, select all of its tracks (Command-A), and drag them all over to the Select Genius playlist in the sidebar. You should now see a dialog box telling you that duplicates are being added. Click on Skip to prevent those dupes from being copied.
Now check out your newly populated Select Genius playlist. You should see all the songs that were in the Genius Mix, without any duplicates. (Because of the de-duping, it may contain fewer tracks than the original Genius Mix.) You can, of course, refine that playlist further—sorting by rating and removing lower-rated tracks, for example, or sorting by artist and removing the ones you don’t want to hear.