[Alan Brinton]

It’s common for melodicas to be factory tuned sharp. Are you checking with an electronic tuner that can be set for A=440, A=441, and so on. If so, check the tuning at A=442. That’s roughly where Yamahas come tuned to. See what it’s closest to, it could be as high as A-443. Then it should be reasonably well tuned (with itself) at that standard. We’ve had a lot of discussion about what tuning standard is most appropriate. Also, try checking the tuning to see where it’s jumping around to when you’re actually playing. It’s desirable to learn how to do your own tuning, which is not hard.