It's in Drop D (D, A, D, G) Just using the top string, though.
Verse — D: —0—0—0—3—2—3—2—0 x4
Chorus — D: 55555—33—7—55555—77—3
It may not look right because I'm typing this out at school, where I don't have my bass.
When I get my bass, I'll tab this one out again so it's right.