Sons recommends using hydrogen peroxide (careful apply it to a paper tower, completely away from the piano so as not to risk a spill onto the keys! And be sure to only use such a small amount that no liquid would drip into the space between the keys). Wipe down keys, then wash your hands! The RPG (Piano technicians guild) recommends this: New recommendations from PTGPiano Technicians Guilds has recently published the document “Covid-19 and Piano Care”.
Their general recommendations are:
- Use alcohol-based disinfectants, do not use bleach-based disinfectants or any product containing citrus as this may discolor the piano keys.
- If using a spray or liquid bottle, use a disposable towel. Put the disinfectant on the TOWEL and not the piano!!
- After use, immediately put the towel or disinfectant hand wipe in the trash and wash your hands as the CDC recommends. Do not use reusable towels or cloths which could spread germs.
- Always follow up with a dry towel and never leave any liquids on the piano or keys.