Ambient Noise (in the beginning) :
Gently strummed constantly

e|--------------------------------|
B|--------------------------------|
G|--------------------------------|
D|-0------------------------------|
A|--------------------------------|
E|--------------------------------|

The tiny piano bits :

e|--------------------------------|
B|-7----5-------------------------|
G|---------2----------------------|
D|--------------------------------|
A|--------------------------------|
E|--------------------------------|


e|--------------------------------|
B|--------------------------------|
G|-4----2-------------------------|
D|---------0----------------------|
A|--------------------------------|
E|--------------------------------|


As for the deep piano strikes.... This is just what sounds right to me but it's open.

e|--------------------------------|
B|--------------------------------|
G|--------------------------------|
D|--------------------------------|
A|--------------------------------|
E|-0------------------------------|