Four-time Grammy nominee Ariana Grande delivered an emotional tribute to her idol, Aretha Franklin, on Thursday’s The Tonight Show Starring Jimmy Fallon. The 25-year-old Grande was at the show to promote her fourth studio album, Sweetener, out today. She arrived at the Tonight Show expecting to merely participate in a comedy sketch. But she was then asked to sing a song with backing by house band The Roots as a tribute to Franklin. After the performance, one report…