Anybody who's been following Katy and Rihanna will be able to tell you Katy sings a lot better love. Sure she has her off moments but when she's on, she really does sing well. Rihanna however rarely sounds good, and her sings are by far much easier to sing than Katy Perry. Teenage Dream and Firework are pretty hard songs with a lot of high notes all over the place, yet she manages to give some good performances. Rihanna is just disappointing.