Music can easily be a-political, but it can never be a-philosophical. I think that's the difference I'd make. For example, outside the National Socialist Black Metal scene pretty much all black metal is a-political in a classic sense, and I doubt most in the scene would see anti-christian polemics as a political statement. Indeed, black metal was pretty much founded on an a-political basis: it was one of the things that made the still bleeding genre split with death metal in the kate eighties/early nineties so violent. Black metal purists cast death metal that dealt with politics as 'life metal' and essentially ostracised it, and the rest of the genre by association. Still, by a general rule, metal is normally not overtly political, and where it is, it is most often in the realms of philosophy rather than society. Even the aforementioned NSBM as often as not doesn't make really overt political statements, except in the odd song. Most politics in metal is on a more subliminal level. For example, Iron Maiden's '2 Minutes to Midnight' carries basically the same message as Bob Dylan's 'Masters of War', without actually saying so unless you read it/hear it properly and know a few basic facts (Such as what the title means). That said, there are the odd few bands/songs in metal proper that are overtly political or have some overtly political songs: Napalm death are a common example, and every single band Martin Walkyier has been in has ended up churning out album after album of his dense and allegorical mixture of left wing working class politics, ecosensitivity and paganism. Other bands have the odd song: Edge of Sanity placed 'Enter Chaos', a brutally vicous and strong attack on gun ownership (particularly American gun ownership: "Gun propaganda, from the 'land of the free', the land of pain and misery!") in the middle of an album that was otherwise packed full of classic mopey Dan Swano existentialism and pure fantasy/sci-fi.
Anyway, that was a bit rambling. I do like political lyrics, btw. As long as I agree with the politics: I can't stand 'Meat is Still Murder' by Propaghandi, much as I like a lot of their other stuff, and even though their musicianship is insanely excellent, I find it hard to swallow Arghoslent's blatant racism.
EDIT: I do like SOAD. The song actually says 'Why doesn't the President fight the war, why does he always send the poor', and I think it's a valid point. It also lead to a fun debate with my mates last night about how effective a soldier GW Bush would be.
