A well maintained piano should only need to be tuned once a year. It can be a false economy to leave it longer than this between tunings. The piano might still sound fine to your ear but it is gradually dropping in pitch. This is because the tension of the strings exerts a pressure equivalent to 18 tons on the piano. Strings stretch, tuning pins unwind and even the frame continuously compresses. If your piano has not been tuned for a number of years then we recommend tunings every 6 months to gradually bring your piano up to concert pitch again.