The online radio service Playback.fm streams top 40 radio from a number of decades. A feature of the site allows users to find what song charted at #1 on the day he or she was born.
This service can also be used to find out what songs were #1 on any given day, all accessible by simply punching in a date. Whether you were born in the late 60s or the late 90s, Playback.fm gives an incredible scope on the hits of the last century. For example, on Skrillex's birthday, January 15th, 1988, Whitney Houston was sitting at the top of the charts.
So now we know why Sonny grew up to sing in an emo band :)
Visit http://playback.fm/birthday-song to check out the feature!