Confession time, I've played it four times now and the third and forth were spent improvising along with it.....my theory not being brilliant I don't know if it would be written down this way but what you were doing hinted at lydian mode to me, so I started playing lydian starting on c over the a root chord. If you haven't tried that have a go...it gets boring doing the whole track that way but it's some spice to add to the main meal.
I know it sounds cheeky but is there any chance I could have your backing track so I can record a couple of those ideas and post them in this thread? I really love that rhythm, it puts me in mind of something by Hendrix but I can't think what it's called.
'There's no such thing as bad weather, there's only the wrong clothes...'