Home / Forums / General melodica discussion / P-37D wildly out of tune? Also: delayed key sound. / Reply To: P-37D wildly out of tune? Also: delayed key sound. Reply To: P-37D wildly out of tune? Also: delayed key sound. February 17, 2022 at 10:17 pm #14043 Pál KrammerParticipant An update on my P-37D tuning: well, as both Alan and André predicted, even doing nothing the tuning will change over time and also as the instrument is played. I’ve observed that even when my melodica is dry the tuning will be different from last week. So, rather than chase small variations in pitch over time and playing conditions, I think the safest course of action is to identify which keys are consistently out of tune by about 15 or more cents and focus on correcting those. Fortunately, there aren’t many.