Never trust a website that claims "Instant 1-click conversion" without showing you the MIDI channel mapping. Take the extra 30 seconds to export natively from MuseScore. Your future self—opening that MIDI file in a professional studio—will thank you.
if not mscx_file: return 'success': False, 'method': 'music21', 'error': 'No .mscx file found in archive' convert mscz to midi verified