Here is a video where you can see Sean Hayes play the song: (search YouTube for k4OEg8N-R4k because forum rules don't allow a noob like me to post the link). There, the chords are sounding just as described above, but I believe he is fingering Am, G and Em chords. Would you agree with that and conclude, like me, that he is tuning his guitar down 3 semi-tones?
Sorry to revive this old thread, but I thought it would move this discussion forward on a song that I love and want to play. There is almost nothing on the Web about this song. The post above is what got me to join the forum.
Thanks for your help!
h_m