The Eve Of The War by Jeff Wayne is in Gm at 120 beats per minute and runs 8:27 across 22 bars. It uses 5 chords — Dm, A7, Bb, Am, C. The chord diagram changes as the song plays and the words light up as they are sung, so you can strum and sing along without reading ahead.
Want the melody line note by note? The Eve Of The War guitar melody tab.