for this song you need to tune your A string down so that its 7th fret matches your open 
string. Mark used a two string bass in this tuning.

--------------------------------|
-7-7-7--777--4-4-2--2-2-2-------|
-7-7-7--777--4-4-2--2-2-2-------|
--------------------------------|

-------------------------------|
---5--5----5-5-----4-----------|
-5---5-5-5--5-5-4---4-4-4------|
-------------------------------|
somedaay.....