Try using a piece of clean cheesecloth lightly dampened with water to clean the keys. Make sure any excess water is quickly removed to ensure water does not run between the piano keys. When cleaning the exterior of the piano, follow the instructions above, again, with a soft dry cloth remove excess moisture from the piano case work. If the piano has a wood finish, always wipe in the direction of the grain. This will help to remove any build-up of dust. Internal cleaning can be carried out at the time of appointment, if and when required.