This song came about almost by accident, as a last-minute addition to the album Hysteria. While on a tea break, lead singer Joe Elliott was jamming on an acoustic guitar with a riff he had, and the producer loved it, suggesting it be developed into a song. They quickly put together a sketch, feeling they were onto something special. The rest of the band then helped complete it within two weeks, resulting in a track that became a signature song for Def Leppard, blending glam metal, hard rock, and pop rock. It plays like a spontaneous burst of energy that just had to be captured.