The Guardian: Rihanna and the rise of raunch pop:
S&M marked a pivotal moment for pop. In 2007, Rihanna told Paper magazine she aspired to be “the black Madonna”, and it’s possible S&M was her calculated attempt to top the level of infamy her heroine once attained, but she could just as well have taken her cues from the generation of phenomenally successful good-girls-gone-bad that preceded her: Britney Spears and Christina Aguilera. Their own transmogrifications from wholesome teen stars to FHM poster girls upped the stakes for future pop princesses, who must wear less and promise more to make the same impact on an over-stimulated audience. Pop music has reached a point where it’s most successful young women are shooting whipped cream (Katy Perry) and fireworks (Lady Gaga) out of their bras.