[Kevin]

I agree that stretch tuning isn’t appropriate for the melodica. It’s mostly in the highest and lowest ends of the piano the stretching occurs. In the middle where the melodica lives the notes are I believe standard.

I’m curious about the technique you guys are using?
Do you Scape and then completely reassemble?
I tried using pieces of electrical tape to cover all the screw holes on the air-chamber cover. Then while wedging the key open with something and using the hose I hold the cover down with both hands and test the note. I don’t have the patience to screw the thing back together over and over for every note.
The issue I’m running into is how tight I hold the cover has a bearing on how the notes sound. Unless I hold the cover as tight as I can I often find the reed is no longer in tune when I do put the screws back in.
I assume it’s similar to bending a note.
Also I always use sandpaper never a file. Similar to this tutorial:

I always thought that a file would be too destructive?

As far as tuning by ear. I try to make sure the octaves are consonant. No matter what the needle says I check the octaves by ear.

Alan, I feel a little guilty for convincing you to tune in 440. If you are going to play solo I think it’s acceptable to bring a melodica in tune with itself.