The classic rock anthem 'Sweet Child O' Mine' by Guns N' Roses was born from a simple guitar exercise. Lead guitarist Slash was playing a 'circus' melody as a warm-up and a joke during a rehearsal at a house in the Hollywood Hills. Rhythm guitarist Izzy Stradlin liked the melody and began playing chords underneath it, and bassist Duff McKagan soon joined in. Lead singer Axl Rose was upstairs in his room and heard the music through the floor; he immediately began writing lyrics based on a poem he had written for his girlfriend, Erin Everly. The core of the song was reportedly written in just five minutes. Ironically, Slash hated the song for years, dismissing the iconic opening riff as a 'silly' string-skipping exercise, but it became the band's only number-one hit on the Billboard Hot 100.