Wasn’t too hard. Added the plunger and positioned Jazz Guy’s hand.
More reference video of how this plunger is going to be used:
Update: Added the clip of the music I’m using. It’s the last 30 seconds of Trombone Cholly:
It’s slow, sloppy and not in time with the music. It’s to make sure my constraint on the hand is working with the slider. So far so good.