NEW YORK - SEPTEMBER 12: Linda Perry and Christina Aguilera attend the global launch of The Montblanc John Lennon Edition wri
Stephen Lovekin/Getty Images

Singer/songwriter/producer/all-around-badass-rock-chick Linda Perry has a multifaceted career that's seen her conquering the music biz for more than 25 years. As the lead singer and primary songwriter of 4 Non Blondes, she wrote one of the greatest karaoke songs ever—the band's 1993 hit single "What's Up?" 

And on her own, she's written and helmed some of the greatest pop and rock gems of the last decade: Pink's "Get the Party Started," Gwen Stefani's "What You Waiting For?" and a slew of signature Christina Aguilera tracks, including "Beautiful," which won them both a GRAMMY award.

On her 49th birthday, celebrate one of the industry's most beloved songwriters with some of her greatest hits. From hit singles to the more obscure tracks—don't judge Kelly Osbourne's "One Word" until you've heard it!—get into it all below.

And of course, happy birthday, Linda!