Hi! Thanks for the comment! The music is made with the ADLPlug VST which uses the MAME emulation core of the OPL chip used in adlib soundcards / the sega megadrive etc. It's a free download from here: https://github.com/jpcima/ADLplug
No problem! There are direct downloads of the VST here: https://github.com/jpcima/ADLplug/releases/tag/v1.0.2