Former `` Idol '' judge Paula Abdul returned to the show to participate in the tribute to Cowell , along with many former winners , including Kelly Clarkson , Carrie Underwood , Ruben Studdard and Fantasia Barrino . He replaced David Bowersox in season 2 . The show also is the last for judge Simon Cowell . Former ` ` ' '' judge Paula Abdul pays tribute to him . Janet Jackson , Alanis are among performers on finale .
He replaced David Bowersox in season 2 . The show also is the last for judge Simon Cowell . Former ` ` ' '' judge Paula Abdul pays tribute to him . Janet Jackson , Alanis are among performers on finale .