Start the soundproofing procedure with your roof absolutely revealed. Drywall must be eliminated and anything that might be below it, making only the wooden supports revealed. Do not damage the drywall, as it will be faster and simpler to use than having to evaluate and cut new wood pieces. Once you are done doing this, make sure you have the required equipment and material ready on the table. Now you can actually start making the ceiling or wall soundproof.
Use the froth insulating material to firmly pack the areas between the revealed wooden struts. R12 or R13 froth insulating material performs absolutely brilliantly on walls and ceilings. The R catalogue represents the solidity of the froth and how well it wards off noise and other disturbances. This froth is will be acting as the first layer of defense against any sound through the walls and ceilings.
Consider identifying any little openings that may need to be sealed before starting the actual process. Even a very small area can let travel a lot of sound inside. If any breaks or little gaps are found, use a dab of the caulk to close them.
Fit a part of froth over your roof or walls. The most convenient way to do this is to buy formerly designed soundproof roof and walls material such as tiles. There are a number of organisations that provide these and they fit well into any roof without coming off. Keep in mind, though, that sound experience more resistance when travelling through denser objects. So it is advised to purchase the tiles as dense as you think the walls will require.