Q. How often should I tune my piano?
A. At least one tuning per year.
Q. Is my piano un-tunable and or damaged as a result of not having it tuned in 10, 20, years or more?
A. It may have damaged your ears, but the piano is probably fine. The pitch will be extremely flat. The piano will need a Pitch Raise and a follow up re-tuning after one month.
Q. What is a pitch raise?
A. It's a rough tuning to return the piano to A440 Concert
Pitch.
Q. Is it necessary to tune my piano at A440 Concert Pitch?
A. No. Recommended, but not necessary.
Q. Do you use a machine or tune by ear?
A. I'll use either depending on the piano's tuning history,
make, and other variables.