Play music files immediately in the Finder with Quick Look
You can play any song or audio file directly within the Finder by using Quick Look. Just select the audio file and then hit the Spacebar or Command+Y to bring up Quick Look and start playing the song. You can also scrub around within the song which makes it a great way to see if you like a new song that you just downloaded from a music blog or elsewhere.
I mentioned this briefly when describing a problem when iTunes won’t play a song but it would play in Quick Look, and realized that many people might now know that Quick Look can play songs too. This is a great feature of Mac OS X, so start using it!