The main riff is played through the intro and most of the verse..
E|----------------------------------|--------------------------------|
B|----------------------------------|--------------------------------|
G|----------------------------------|----------------0---------------|
D|--0---2---4---7---4---4-0-2---2-0-| 0---2---4---7---7-6-2-0-2---2---|
A|--0---0---0---0---5---5---2---2---| 0---0---0---0---x---x---2---4---|
E|--0---0---0---0---5---5---2---2---| 0---0---0---0---5---5---2---2---|


aside from that, the chords used in the verse are some sort of E7, what I think is GM7 
and Bm
in drop D and in the context of the song, they look like this:

    E7  G7  Bm
E|----------2--|
B|----------3--|
G|----------4--|
D|--0---4---4--|
A|--2---5---2--|
E|--2---5---0--|

The chorus uses a bunch more chords..the names may not be proper, but..you get the idea 
least


  A/F#  G7  D   C   G5
E|----------2---0-------|
B|--2-------3---1-------|
G|--2---2---2---0-------|
D|--2---4---0---2---0---|
A|--4---5---0---3---5---|
E|--4---5---0-------5---|


For the part where it's just the riff, I'll just put 'riff'..
theres a '*' in there, where I'm not really 100% sure about what's going on..but I think 
close..

anyway, here goes-


(riff)
If you hated music


would you be a mother with a family?

(riff)
if your songs weren't written

                                    E7
would I still get shivers from your silence

G7              Bm        G7       (riff)
until tears are welled up in my eyelids?

(riff)
if your duty wasn't earthly


would you understand it's beauty?

A/F#                       G7
please do these things for me

A/F#                      G7                D      E7              C     G5
please know that you have held one thousand years (by one thousand fingertips)

(riff)

(riff)
if your words weren't charming


would they still sit on fences in my eardrums?

(riff)
if your voice was harmful


would it be a stormcloud

      *E7     G7     Bm       G7       (riff)
on the golden bay of summer's starting?

(riff)
if I didn't know you


I would not be nearly as inspired

A/F#                       G7
please do these things for me

A/F#                      G7                D      E7              C     G5      C G5
please know that you have held one thousand years (by one thousand fingertips)