I haven't the foggiest of an idea of what they're called, but what you could do is try and figure out what frets he's playing on etc. If it doesn't sound right, he's probably in a different tuning. If that works, figure out the names of chords he's playing. Do that, then you can figure out a key based on the progression. See what "position" (eg. Tonic, Dominant, Sub Dominant etc.) each chord is in that key, then apply those to other keys. In other words, figure out why they sound the way they do in the key, then you can apply the rule to other keys.

Not sure if this helps, but I hope it did a little - Chris