Yeah, that's a great one. Am7add9. Satch uses one of those in "Tears in the Rain".

Try reversing the B and C in the fingering. Makes it a little easier to play.




E |---------3---------------------|
B |-------0-----------------------|
G |-----5-------------------------|
D |---2---------------------------|
A |-0-----------------------------|
E |-------------------------------|



By the way, James, I do have some Celtic sheet music. But it requires tuning your guitar to all these funky alternates.