Max Martin (real name Martin Karl Sandberg) started writing songs for other artists after he left his band It's Alive. He wrote songs for Ace of Base, Backstreet Boys and Robyn, and he eventually penned a tune called "...Baby One More Time." The song was turned down by Backstreet Boys and TLC before being recorded by a newly-signed 16-year-old named Britney Spears. It became his first No. 1 on the Billboard Hot 100 January 1999.
The following year, Martin co-wrote "It's Gonna Be Me" for N Sync which also went No. 1. He had to wait eight years for his third No. 1, Katy Perry's "I Kissed A Girl," but since 2008, Martin has averaged two-and-a-half No. 1 hits a year.
Only six songwriters have written more No. 1 hits than Martin. Paul McCartney holds the record with 32, followed by John Lennon with 26, Mariah Carey with 17, Barry Gibb of the Bee Gees with 16, and Brian Holland ("Please Mr. Postman" and "Stop! In The Name Of Love") and Sean Garrett ("Yeah!" and "Goodies") with 15.