It would be this one.
Here’s Why
This is a shoulder exercise that addresses your rotator cuff muscles.
I see issues in this area for so many musicians and it contributes to so many of the issues that musicians face. Neck pain, mid back pain, shoulder pain, as well as pain and tension into the wrist, forearm and hand.
Your shoulder creates a stable base for all the other muscles in the arm to work on. If that base is unstable, all those muscles down the arm have to work that much harder.
I got you started exercising this muscle group with the sidelying shoulder rotation exercise. But let’s face it, your music demands more of your rotator cuff.
The shoulder rotation with the band is a good intermediate exercise that will challenge those muscles more. It will help those little muscles meet the physical demands your music puts on your body.
More Details
Do this exercise as a tempo of 3 seconds out, then 3 seconds to return.
Perform 8-12 repetitions for 3 sets on each side.
It is a strength exercise, so it’s best done 1-3 times per week.
If you need some bands, here’s a good affordable option with 3 levels of band strength.