Mars Miller's Jean Pierre, tips


Hi everyone! It’s been a while — I hope you’re all doing well! I enrolled in a jazz school last month, and for the student concert, seven other musicians and I are going to play “Jean-Pierre”, the jazz-rock tune by Miles Davis.

I came across this version with a harmonica:
https://www.youtube.com/watch?v=bYNRZMa-XJE&list=OLAK5uy_lCFJBeRA5I5DI24FGjbUP4X8XJ4TmKfy8

Since the tune is in A, it seems like he’s using a D harmonica in second position — does that sound right to you?
Also, since the whole piece stays in A, how do you think I should approach improvisation? I’m comfortable improvising over a blues progression or a II-V-I, but if I have to stay in A throughout my solo, I’m worried it might get boring.

Do you have any suggestions?
Thanks in advance!