A python-based MusicXML player, synthesizer, visualizer! You can create your own instrument sound, export the sound and even customize its UI easily!
Here is the video introduction of the program: https://www.youtube.com/watch?v=JhhEX2APhsg
Here is one video example of the program (background is changed for fun): https://www.youtube.com/watch?v=FJd40BSjg4I
If you cannot install simpleaudio module, sheck this website's answer: https://stackoverflow.com/questions/45007577/pyconfig-h-cannot-open-include-file-io-h-no-such-file-or-directory