I agree that having a melodica in tune with your ensemble is one way to gain respect and acceptance of this incredibly versatile instrument. I’ve been performing with classical music ensembles, and at first the audience isn’t quite sure about the instrument when they see it. Until they hear it. Then they almost like it as much as I do.
For my purposes, 440 or 441 is necessary; I also play with a vibes player whose vibes are sharper than that, so I’ve tuned one of my melodicas higher for that purpose. It’s easy enough for my to tune my electronic keyboard to any of my melodicas.
I usually tune keyboards (small acoustic organ and harpsichord) by ear, because I don’t tune equal temperament for my gigs. (I mainly play Baroque music, where there were lots of good sounding temperaments being used that are easily tuned by ear). I also use a Korg master tuner VU meter (discontinued) which is programmable to different temperaments, so I can store temperaments from when I play in ensembles with bagpipes, or Cambodian instruments. One of my goals is to have a melodica at 1/6 comma meantone which restricts the keys I can play in (to about 8), but sounds incredible when playing chords.
I will be having lots of time in the next weeks to devote for tuning my melodicas; so far I have found that tuning to a meter visually actually leads to different results than when I tune by ear to the pitch made by that electronic tuner. I suspect it has something to do with things mentioned in this article (are we allowed to post links?); the crux being that frequency and pitch are NOT the same thing, and results you get by looking at a dial are not the same as what the brain makes out of the information coming in through the ears.
i don’t pretend to understand everything in this article! But as you can tell, I’m a tuning geek. Probably due to tuning and playing organs and harpsichords, which you tune every rehearsal and gig, are easily tuned and have to play chords. Melody playing I am not so picky. But my dream is to have a melodica ensemble (any takers in the western NC area?) and then we would have to be in tune for chordal playing