the "riff" or melody in this song is originally played on banjo.
there's also an acoustic guitar, but i've chosen to tab the banjo part on guitar 
it sounds quite nice!

e-3--6--3------------------------------|
b----------6--3------3--------3--------|
g----------------5-3----5-3-----5-3----|
d---------------------------5-------5--|
a--------------------------------------|
e--------------------------------------|