McElderry sung Take That's cover of Barry Manilow's 'Could It Be Magic'. Friedman choreographed the production.
He told Heat: "My favourite performance of the series? It's a tough one to call, but I think it was Joe's 'Could It Be Magic', with the dancers in the giant frame.
"I was really nervous showing it to Cheryl [Cole] in rehearsal - I was worried she might cut it, but luckily it made it to the show."
He added: "Another highlight was Stacey singing 'Who Wants To Live Forever' - it was the first time I truly believed that she could make it to the final.
"I always thought she had a great personality and a really good voice, but she was an underdog for me."