Just a sample of a song in Project Doomed, which can be found below. Song sound will vary depending on the MIDI/Soundfont setting used in whichever source port used, be it Timidity, BASSMIDI or something else.
Project Doomed is a derivative project from Jay Reichard's Project Doom, which makes the songs slower but also closer to the original MIDIs with instrument and left/right audio settings.
Soundfont used to play back above song: Merlin Vienna
Get Project Doomed here: http://www.moddb.com/members/chrisdragon1/addons/project-doomed
Get Brutalized Overkill RC 1.21 here: http://www.moddb.com/members/chrisdragon1/addons/brutalized-doom-and-doom-ii