We are playing this music in the band. The others want to know how to say this in German. "Common" is a tricky word. I think the composer was intending to say "common" as opposed to "noble", so he meant "ordinary" or "normal".
I can't think of a way to say this in German which doesn't come across as negative. I tried "für den normalen Mann", or "gemein" or "bürgerlich", but nothing seems to fit.
edit: I checked the title, it is an allusion to vice president Henry A. Wallace proclaiming the dawning of the "Century of the Common Man" in 1942. This is probably not the place to ponder on what he meant, but the more I think the less I see it. Politik-speak. I think I'll go for Normalbürger.