Based on what I’ve learned from Meeting Of The Spirits, I think Birds of Fire is: D D U D U - D D U D U - D D U D U - D U D
Check out ‘A Life Devine’ on the Mahavishnu/Santana album from the 70’s.
It begins with an organ part that rises & falls…then Billy Cobham comes rolling in…and then John appears playing a really cool set of descending 3-note arpeggios.
I think John is playing it strictly downstrokes…just sweeping through the G - B - E strings.
When I 1st heard it back in my high-school days, I could barely figure out the notes.
Once I did, I then had to tackle the picking.
It was like walking with my shoelaces tied-together…