The X Factor finalists have battled it out to save themselves from being booted off the reality show.
The 14 hopefuls each had the chance to sing a track by their musical heroes.
Edinburgh-born musician Storm Lee missed rehearsals on Friday after coming down with a virus.
However, despite fears he would not make the live performance, the 37-year-old opened the ITV show with a cover of Bruce Springsteen's Born To Run.
Judge Dannii Minogue told him "you sang that very well" and his mentor Louis Walsh added: "Storm, you were born to sing."
Treyc Cohen also wowed the audience with her performance of Purple Rain by Prince.
Cowell said her performance was "incredible" while Walsh told her that she reminded him of Tina Turner.