Frank Sinatra
Gene Kelly sings: I'm Singing in the Rain, in the 1952 movie: Singing in the Rain.
drizzle
Blind Melon
water
Bruno Mars
The artist Who sings It Will Rain Bruno Mars
superchick
The Doors
Selena Gomez sings it. Rihanna does too, but i personally think that Selena sings it better.
Terence Trent D'Arby
Tay zonday sings it
The Cascades