Drop C tuning.
Main clean riff. (The distorted part is just the same as this as well and doesn't use any chords)
|--------------------------------------------------------------------------|
|--1------1-------0-----0--------------------------------------------0-----|
|----0------0-------0-----0----------0-----0------------0-----0--0---------|
|---------------------------------5------5--------(5)/7-----7------7-------|
|-0----0------0-2-----2------------------------------------------------(5)-|
|----------------------------0-2-------2------2-0---------0----------------|
The chords over the more melodic part towards the end are; Am, C, Em, D.
Melody:
Am C
Ghost Brigade 
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