LMMS now works on OSX (with bugs and crashes)

Rendered the title theme midi from the old DOS game, called CyberMage:
https://www.youtube.com/watch?v=zcRrntnRqWs
Back then mp3 was not yet invented, so all game music was in midi format, usually relaying on a standard sample set, called General MIDI sound bank. Different audio hardware came with different implementations that that sample set, so all game soundtracks of the era performed incorrectly on all but some single audio card the composer had while making the song. Typically composers used high end midi keyboards to produce the songs, which programmers just thrown into the game, so in reality no card may have been compatible.

>>3

all those synthesized instruments would be mastered with equalizers, filters, compressors etc. to achieve just right sound.

Indeed. These early midi modules offered no per-instrument frequency filtering. So if some Korg instrument is nice but has harsh higher freqs, you just cut them off, and maybe replace high freqs from some alternate instrument, usually using custom samples. But DOS sound modules offered no way to do that. But that is not that huge of a problem, since composer can prepare his/her instruments in advance. Playstation 1 had basically the same Roland GM clone, but games came with their own sound banks. Custom samples and uniform hardware made Playstation games sound nice, although a bit limited, due to the sample size limitation.

There were also the so called tracker formats, which were basically midi coupled with samples, and simple post-processing effects. Unfortunately these ran in software, eating large amount of precious CPU memory, therefore not used in games, beside Unreal and Deus Ex, which used them because mp3 decoding was actually more expensive.