Play once as an intro and then these just repeat throughout almost the whole song, he 
only time these shiny be played is when they repeat "Up all night, hey, up all night..."

And during the bridge when Harry sings the chorus and the rest echo "We're gonna wanna 
stay up all night..." start out quieter and gradually get louder until the main chorus 
and play louder.

Enjoy! :)

-Grace

Guitar 1/Bass Guitar
E|-----------------------------------------------------------------|
B|-----------------------------------------------------------------|
G|-----------------------------------------------------------------|
D|-----------------------------------------------------------------|
A|-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-3-|
E|-----------------------------------------------------------------|

Guitar 2:
E|-----------------------------------------------------------------|
B|-----------------------------------------------------------------|
G|-----------------------------------------------------------------|
D|---------------------------------2-2-2-2-2-2-2-2-3-3-3-3-3-3-3-3-|
A|-3-3-3-3-3-3-3-3-5-5-5-5-5-5-5-5---------------------------------|
E|-----------------------------------------------------------------|

Guitar 3 (main tune)

E|--------3----------3----------3------------------3----------3----------3----------|
B|-----------5----------5----------5----3-------------5----------5----5-------------|
G|--5--5----------5----------5---------------5--5----------5----------------5----4--|
D|----------------------------------------------------------------------------------|
A|----------------------------------------------------------------------------------|
E|----------------------------------------------------------------------------------|