Because they play this song in A major key in acoustic version. Original is in D major, which is higher, so Simon sings it more aggressive. Like both of them in different situations)
Sam Lusetti Baby when you hold me: A E F# E So baby won't you take my hand: C# D E F# I am going home: A G F# E And there's no such thing as home: B C# D D You used to stand so strong: C# D E E