Pretty much every pop song you love, from Britney Spears' biggest hits to Katy Perry's “Teenage Dream” was co-written by this Swedish genius.

This is Max Martin.

He is a Swedish songwriter and producer who has written or co-written a staggering number of the biggest pop hits of the past two decades. He is the man behind the most popular songs of the late '90s teen pop boom, and has sustained a career by writing tons of radio smashes with everyone from Katy Perry and Taylor Swift to Bon Jovi and Usher. He's a true genius of pop, and this is the best of his best.

Source: britneyspears.hollywood.com