I’m probably going against the prevailing thoughts here but I’m in favor of A=440.
That’s been a standard for a long time. If you buy any electronic keyboard or other fixed pitch instrument it’s going to be tuned at concert pitch A=440.
I don’t get the tuning the reed high so that when playing it comes down in pitch? People must be playing much louder than I ever have? :-O
If you buy a pitch pipe which works on the same principle of a harmonica you expect it to be tuned to A=440. It doesn’t say in the directions blow as hard as possible to bring the pitch down to correct tuning!
I think this is one of the main offenses that keep the melodica from being taken seriously. It’s usually the last straw.
They see you pull out this instrument that’s plastic with child-size keys and if they have seen one often it’s associated with children or music education. You get a few jibes and chuckles but then the music starts and after a chorus or two of you being obviously out of tune with every other instrument in the band and no way to tune on the fly you are “politely” asked to put that thing down and get back behind the piano!