Studio above garage in bonus room- early planning

Another issue with the cloth knee walls that I forgot to mention... I have theree young kids who all play piano and sing. If they are in the studio, I'm afraid they will lean on the walls and push on them. The fabric will get ripped and stretched and look bad. I just don't know if putting in all the mdf by the styrofoam rafter vents will get me much isolation or not. It would get me two sealed leaves. It would be a lot of work. Any thoughts on that?? Thanks again!