Beyoncé, Mariah - Same R&B/Ballads/Urban music.
Kelly Clarkson, P!nk and Avril - Same pop-rock and ballads.
I don't understand why people are saying Britney, Rihanna, Katy and Taylor.
OOTB =|= Prism
BOMT =|= Britney Jean
Taylor Swift =|= 1989
Music Of The Sun =|= Anti
I guess they just want to mention the ones than don't have powerful voices?

Sorry I forgot (for Atrl) popgirls without powerful voices = untalented, generic, never evolve, basic, etc