Eh the range isn't bad la... if he has already gone through puberty.
But you guys are 16 right?
Not meaning to offend in any way.
If he has already gone through, then he needs to work on his tone and pronunciation. Seriously, the way he pronounces things is awkward to say the least, and makes me go "WTF?" Is he a foreigner by any chance?
Anyway, it's a hard song to sing la, give him some credit at least la.