Hello and thank you for your question.Keys on a digital piano generally can't go out of tune like on a stringed piano. But they can be programmed to different tunings, to accommodate different types of music that use scales that differ from traditional western music.Most likely, the scale settings in your KN7000 have somehow gotten changed. You can go in to the menus and edit the scales to locate what has been changed and set it back to what it should be. Information about these scale settings can be found on page 159 of your manual. Or you can do the brute force method of resetting the KN7000 to its original factory settings. That will reset the scales and everything else. So make sure you back-up any edited data that you don't want to lose, like Sequence, Sound memory, Composer, and Pads.To perform a Factory Reset:
I hope I have satisfactorily answered your question. Please let me know if you need any more information or clarification on this issue.