In reply to kelly.

SOS sucks. I think Rihanna made it slightly bearable as she has such a great tone, which could be said of a lot of songs she had hits with.
Britney and Mary J are meant to have turned down Umbrella, which is a far stupider mistake.
But honestly, I don't think songs like SOS, Only Girl, What's My Name, We Found Love or, now, Diamonds would have found huge success if anyone but Rihanna had sung them.
And I don't even like Rihanna much.