“Crazy In Love” is the ridiculously successful lead single from Beyoncé’s first solo album Dangerously In Love.

Penned by Beyoncé and Rich Harrison, the song revolves around falling in love and doing things you wouldn’t normally do without a care. The inspiration for the song struck after Beyoncé looked at herself in the mirror in the studio and thought she was looking crazy, which lead to Harrison coming up with the hook.

We just couldn’t figure out what to write with it. I was looking crazy with my clothes. And I kept saying, “I’m looking crazy right now” and he said, “That’s the hook!

The song ended up topping the charts in both the US and the UK in 2003, making it the only one to do so in that year. Additionally, it earned the singer two GRAMMY Awards in 2004 for Best R&B Song and Best Rap/Sung Collaboration.

This was the second collaborative effort between JAY-Z and Beyoncé who were dating at the time. Bey asked Jay to write a verse for the song on the night she had to turn her album in. The hook is sampled from “Are You My Woman (Tell Me So)” by the Chicago group The Chi-Lites.