let's guess

Hello people!
Let's play a guessing game.
Guess who is this Pop/Rock singer?
If you someone who were/are into Pop songs,
I am quite sure you know who is he.
You'll be suprised, if you know the answer.
His album will be out on 13 May! :D
P/S: He changed his hairstyle.

Okay, its quite obvious over here.