There are quite a few piano owners out there that do not own a piano cover. I would say that there are probably even a few piano owners that have never heard of a piano cover. A piano cover can be a wise investment for several reasons.
One of the main reasons to use piano covers is to protect the piano from damage. Damage can be caused by:
Dust and dirt – these can wreak havoc on a piano’s finish, as well as getting into the cracks and crevices of the keys.
Children (and some adults) – how many times have you seen a child (or even an adult) beating on the piano keys or climbing all over the top of a piano Pianos should be kept covered to keep the temptation to climb and play on the piano to a minimum. It also lessens the chance of tempting someone to sit down and play a few notes.
Pets – cats love to climb all over furniture and the piano is no exception. A cat’s claws can cause a lot of damage. Dog’s love to chew on things, especially legs of wood furniture.
Humidity – can cause damage to the wood as well as the internal mechanisms causing the piano to require frequent tuning.
Sunshine – can cause fading and damage to the wood finish of the piano.
A few more things to keep in mind about taking care of a piano:
1. When a piano is kept covered, it shows that the owner takes pride in their piano and wants the instrument to be in good shape and last a long time.
2. Keeping a cover on the piano will help keep it tuned and ready to play at a moments notice.
3. Maintaining the piano will also help to retain or possibly even increase the resale value of the instrument, whether for your benefit or your heirs.
4. Most styles of piano covers are available in different fabrics and colors to coordinate with the decor of the room.
5. The cover also lessens the chance of chips and scratches in the finish of the piano.
Taking pride in caring for a piano will make you proud of your instrument and more willing to play it when you get the urge to pound a few keys.

