System Shock Theme MIDI files
How they sound is totally dependent on the hardware they’re being played back from. If you’re stuck with FM synthesis, then they’ll sound like tinny shit coming from a transistor radio. A more modern card that has excellent MIDI support is the Turtle Beach Santa Cruz. Another, though lesser card, is the SB Live! If using a Live!, set the MIDI playback device to Microsoft GS Wavetable SW Synth for best results. I haven’t owned anything other than these two, apart from old Creative cards like the AWE23, the SB16 and a couple of ESS cards like the Maestro.
For other, non-Origin, music stuff, try this page.
Some of the Ultima Underworld 2 MIDI files have invalid play times like 40 odd minutes. They actually average about 1 minute for each of them. I don’t have a MIDI file editing program to correct this, but seeing as it’s mainly cosmetic, I’m not too fussed.