You can't really define good music. But you know it when you hear it.

So it's about time your computer did too.

Here to dig you out from an avalanche of unlistenable B-sides, one-hit wonders and the occasional ill-advised late-night Black Eyed Peas download now cluttering your hard drive: Mufin, the equivalent of a mash-up between your iTunes library and your Pandora account.

In short, it's a music player with two major advantages over your current system. First, it listens to you—well, not so much you as what you're listening to. So by analyzing the songs in your existing iTunes library, it can automatically create playlists based on, say, tempo or "sound density" instead of attributes like genre or name. (The system was created by German researchers—those guys really know rock and roll.) The upshot: your next romantic evening won't be interrupted by fumbling for the skip button when Sinatra somehow segues into Slayer (or vice versa).

Mufin also brings powerful music suggestion into play, just in case your library's Motown-to-death-metal ratio needs a little fine tuning. Select a song you like and it searches millions of songs to find ones that literally sound similar to the one you've selected.

So you won't get lost in the shuffle again.