You could even say this is the whole song, not only the intro, but I'm not sure.
There is probably a bass line playing on D, A and E. But.. well. Meh. Nice and melodic
Am Am/G
E||----------------------------|-----------------------------|
B||-----------------1----------|-----------0-----------------|
G||-------2-----------------2--|------------------0----------|
D||------------2---------------|-----2------------------0----|
A||--0-------------------------|-----------------------------|
E||----------------------------|-----------------------------|
G Dm
|----------------------------|------------1----------------|
|--0-----------------0-------|--3-----------------3-----3--|
|--------0-------------------|-------2---------------2-----|
|--------------0--------0----|-----------------------------|
|----------------------------|-----------------------------|
|----------------------------|-----------------------------|
Am
|----------------------------|-------------|
|-----------------1----------|-------------|
|-------2-----------------2--|--------2----|
|------------2---------------|-----2-------|
|--0-------------------------|-------------|
|----------------------------|-------------|