shed studio revised!

here is my final plan for my walls, ive allready framed studs as part of the outer leaf. I was hoping I could use chipbord between the studs as I can get this for free. I will use simular construction for the cieling but without the concrete. Does anyone see any flaws, my nieghbours are about 20 feet away. Do you reckon I could get away without the concrete, but then I will be playing drums in it. Conerning last post............I always have to learn the hard way doh! Thanks For reading.