NB We do not recommend MIDI files for practice tracks sent to others. MIDI will work, but PlayScore provides a better way. If you use this PlayScore feature recipients will see the music and follow along just as you do. This feature is free for the recipient. Please see Preparing practice scores for a choir or ensemble, or watch this video.
Creating MIDI files
In PlayScore you can export a MIDI file to play on any mobile or desktop device and sound as the music did in PlayScore 2.
Whatever adjustments you make to the music: voice volume, transpositions, instruments , tempo, repeats and so on are reflected in the exported MIDI file. However, note that MIDI is not the same as a recording. MIDI is a standard for controlling (electronic) musical instruments. When a MIDI file is played on another device it plays using the instrument sounds on that device. This means that the sound of the instruments will probably be somewhat different.
To share a MIDI file, open the document and from the Play screen, tap the export icon 
and choose ‘Save as MIDI’.
MIDI as music notation
We don’t recommend that you use MIDI to export music to a score editor such as MuseScore, Finale, Sibelius, Noteflight or Dorico. Use MusicXML instead. MusicXML contains much more of the printed music than MIDI does. Only through MusicXML export will you get the full richness of the original notation.