What is the most suitable sound insulation material for piano room? (Plate structure of classroom partition wall)

Professional treatment is:

1: partition wall 1-2 cm, new light steel keel wall with sound insulation cotton.

2; Non-woven fabric is pasted on the surface of light steel keel wall to prevent the dust of sound insulation cotton from going out.

3. Add a layer of large core board on the surface of light steel keel wall as the firmware of sound-absorbing board.

4. Paste the mineral wool sound-absorbing board.