What are some alternatives?
When comparing WhatSong and Google Play Music, you can also consider the following products
Midomi - midomi.com find and discover music and people.
Serendipity by Spotify - Map shows when two people play same song at same time
Shazam - Shazam is a mobile app that recognizes music and TV around you.
Last.fm - The world's largest online music service. Listen online, find out more about your favourite artists, and get music recommendations, only at Last.fm
SoundHound - SoundHound - the most immersive music search, discovery and play experience on mobile.
Pandora - Pandora Radio is a free (ad-supported) internet radio founded in 2000.