When soundproofing a ceiling the method that will provide the best results is to provide several layers of soundproofing. First you want to install some fiber glass insulation between the rafters.

Then you want to install three layers of materials that will provide a proper soundproof barrier. The first layer is plywood, the second layer is fiber board, and the third layer is drywall. You also want to seal all the cracks with calking as you apply each layer.

The last layer is a pillow drop ceiling. Build a T-Bar drop ceiling of about 6″. Install standard grid type lighting reflectors in all grid spaces. Then fill the 6″ space with pillow type material. This will provide the maximium soundproofing and will provide the best acoustics in the room.