Somehow I couldn't get the MKR 1010 to find my midi stream over Wifi, so I switched to Sparkfun's ESP8266. My present version works as follows. I have sheet music in MuseScore on my laptop. I have rtpMIDI installed on the laptop. MuseScore plays the score and sends midi to rtpMIDI, which sends it via Wifi to the ESP8266. The organ plays the tune. Any tune I write or download from MuseScore.com, as long as I change the instrument to Harmonium or Reed Organ. Some restrictions, though. A 16th note is the shortest in standard tempo 120 bpm. And even quarter noter are hard, if same tone is repeated. I have to shorten them to dotted 8ths to give time for key to come up before going down again. But it works great! A big challenge would be the Flight of the Bumble Bee. It might work with a bit of arranging and single note editing. Where same tone is repeted rapidly, I'd change it to octave tremolo.