Here are the three apps I've mentioned on the air as means to identify a song that is playing and who performs that version.  All three have saved me some sleepless nights.  Click on the icons to find out more about the apps themselves.

  This one is called Shazam.  It's the most popular.

This one is SoundHound.  Also very useful and quick.

This one is Tune Up.  When the previous two can't help, sometimes Tune Up can!