The singer, who found fame on ITV1 reality show Popstars, said that his dad was on his mind when he performed every Friday.
"Rolando [Villazon] talks about the turbulence inside the singer and the fact that you have to channel that and find the calm," he told This Morning.
"You have got to completely compose yourself and my thoughts on Friday nights are, 'I'm doing this for my father'. He always had a dream that he wanted me to become an opera singer."
Campbell also defended the show from accusations that it was dumbing down opera for mainstream audiences.
"If this is something that has brought a classical and archaic art to a wider audience, then we should celebrate it," he said.
Campbell, Danny Jones, Marcella Detroit, Kym Marsh and Bernie Nolan are the remaining popstars in the ITV1 show, which airs on Fridays at 9pm.