It is available as an app on both android and Apple devices. SoundHound can identify a song in seconds from your device and has the added ability to figure out the name of a song by hearing you hum it.
It is one of the founding music listening apps on the market. Shazam even offers you the option to purchase the song for download if you would like.
All you have to do is hold your device near the device that is playing the song. Shazam is a popular song-identifier app that works on most smartphones and even has an extension for web browsers.