1. Katy Perry. She knows three notes: Talk, yell and shout.
2. Rihanna. She recognizes that "ella" rhymes with "ella," and can dance, but she's monotone.
3. Ke$ha. I don't even think her "rapping" voice. It sounds computer-manipulated in the vein of Johnny Bravo.
4. Miley Cyrus. She seems to be following the career trajectory of Hilary Duff, meaning she'll be working at Sonic by 2015.
5. Justin Bieber. Maybe I'm missing something, but it seems that Selena Gomez most of the talent in the relationship. And we're not talking about all that much talent to go around.