Lady Gaga, fresh off one of the highest-grossing tours of all-time, will be mentoring the final four American Idol contestants next week as they prepare to perform songs by songwriting duo Jerry Leiber and Mike Stoller. Yes, those Leiber and Stoller classics like “Love Potion No. 9,†“Stand By Me,†and “On Broadway†just have Lady Gaga written all over them. Take it away, Jimmy Iovine! [AmericanIdol/Twitter]