All right the sound card isn’t technically required, but without it, what would be the point? Frets of Fire requires Python, SDL, an OpenGL graphics card, and a working sound card. The latest release is version 1.1.324, which supports Linux, FreeBSD, Windows, and Intel Macs (not PowerPCs, for now).
Once you have your hardware set up, download the latest Frets of Fire release for Linux. If you’ve been looking for an excuse to purchase a wireless keyboard, run out and buy one. It is both slower and unnatural to play with the keyboard on your desk, and if your keyboard’s cord is tethered to your mouse or other device cables for aesthetic appeal, you’ll be in trouble. You do need to actually have elbow room and ample cable to play. Southpaws need not worry, though - the keys are configurable. The default setup uses F1 through F5 as the five fret keys, so if you hold your computer keyboard like a guitar (and I know you do), it is set up for right-handed play. When they reach the front, you fret the notes in question by holding down the corresponding keys with your fret hand, and you “pick” the notes by hitting the Enter key. With the backing track to a song playing, notes scroll towards you in real time on a simplified guitar fretboard. Game play is similar to the commercial GuitarFreaks and Guitar Hero series. If you are not aware of that now, you will be after playing Frets on Fire - a cross-platform, GPLed music game from Unreal Voodoo, where your PC’s keyboard is the instrument and you play lead.