Having an issue w my 1974 MK VI Alto. Regardless of MP used, all notes above high G are sharp. MPs vary from a Lawton to a Morgan to a Fobes and all w the same result. In tune at the low and middle octaves. But up higher, all are consistently sharp. All MPs are adjusted to a very similar...

I have a Tenor sax Bb it is about 9 years old and is a Unison SX602. The problem is the high D,D#E F F# are all about a semitone sharp. Why is this and is there anything that can be done? The F# is practically G. Any ideas?