Katy doesn't really have any particularly amazing songs imo. "Firework" and "E.T." are her best but not masterpieces. I don't really drag her that much (mainly because I couldn't care less about her), but...
Gaga - Just Dance
Britney - Piece of Me
Beyonce - Baby Boy
Rihanna - Disturbia
Katy - IKAG
Bieber - As Long As You Love Me
Selena - Like a Love Song
Janet - That's the Way Love Goes
Nicki - Starships
Lana - Dark Paradise
Avril - Complicated
Madonna - Vogue
Xtina - Genie in a Bottle
Ke$ha - Tik Tok
Kylie - CGYOOH (probably the only I've heard anyway)
Kelly - Already Gone (I think?)
Gaga - Just Dance
Britney - Piece of Me
Beyonce - Baby Boy
Rihanna - Disturbia
Katy - IKAG
Madonna - Vogue
Ke$ha - Tik Tok
Kylie - CGYOOH (probably the only I've heard anyway)
Kelly - Already Gone (I think?)
Because of you is way better than already gone. Great choices for everyone besides Rihanna.
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