Shazam is a popular utility that provides you with information regarding the songs you're currently playing on your computer. The application is very simple to handle: launch Shazam, start playing the song on your Mac, and let the program offer you the info you need.
You don't need much computer experience in order to use this tool. The app doesn't have any settings to configure. You just need to have a built-in or connected microphone and that's it. Once the app identifies your song, it will list its details and give you direct access to the iTunes store page from where you can acquire the track.
Unfortunately, the application occasionally fails to identify songs. In my testing, it didn't detect the Depeche Mode - Enjoy The Silence song, a very popular tune. However, on the homepage of the developer it appears that it was previously identified. Still, this event rarely takes place.
Another thing that bothers me is that, unlike the Android version of the app (which I tested on my mobile phone), it takes a while to identify tunes.
In conclusion, even with the aforementioned flaws, I still think Shazam is worth a shot, especially since it comes without a price. Hence, you have nothing to lose if you decide to give it a try.