[leoB]

Progression I - III(instead of iii) - I - biii(#5) - vi - IV - VII(instead of viiº)

Silverchairs' Across the Night

A - C# - A/E - F(#5) - F#m - F#m/E - D - G#

Does anybody have any idea of what this is? It's marvellously beautiful.
I've been playing for quite a time but never have paid any attention to theory. I've played mostly by ear and through tabs.