Given the unpopularity of the war in Iraq, it’s odd there haven’t been more heavy-metal protest songs. Perhaps that’s a sign of metal’s shift toward conservatism, a shift that has accelerated since Kurt Cobain thrust upon metal a near-fatal self-consciousness more than a decade ago. It wasn’t always this way: in the late ’80s and early ’90s, thrash metal’s progressives were so eager to dissent, they’d protest wars that had long since ended. Metallica spilled angst over the Spanish Civil War ("For Whom the Bell Tolls") and, later in their careers, the First World War ("One"). Fears of atomic armageddon yet to come haunted Nuclear Assault; Sacred Reich’s "Surf Nicaragua" was the "Holiday In Cambodia" of its day. Countless bands, including Megadeth and Slayer, pointed with their very names toward the horrors of war and evinced an anti-war bent in such songs as Dave Mustaine’s "Peace Sells, But Who’s Buying?" and Tom Arraya’s gleefully gory metaphor for the draft, "Mandatory Suicide." All of which were descended, of course, from the mother of them all: Black Sabbath’s immortal "War Pigs."

Now that there is an actual war to protest, metal’s militias have gone silent; its howitzers are muzzled. On this year’s Ozzfest — which had it been held 15 years ago, or 30, might have been as politicized as, say, NOFX’s punk-voter brigades — the only protest tunes will be musty oldies, with one conspicuous exception. That would be a woman who calls herself, and her band, Otep. Signed to Capitol, the group have made a stunning piece of anti-Bush propaganda titled "Warhead." The song itself is a gnashing, death-metal-inflected call to arms; the video, which has gotten play on MTV2’s Headbangers Ball, is at once hipper and more stylized than Moveon.org’s ads, angrier than Michael Moore’s Fahrenheit 9/11, and more intense in a strictly metal sense than, for instance, Slipknot. Images of gas masks, oil wells, and the visage of G.W. are punctuated with slogans as blunt as the song’s riffs — bluntness being not just metal’s chief limitation but also, in time of need, its greatest asset. You can see the video at www.otep.com; you can catch the band on the second stage at Ozzfest, which — featuring Sabbath, Slayer, Judas Priest, and more than a dozen others — kicks off at Meadows Music (860-548-7370) in Hartford on Saturday and hits the Tweeter Center (617-931-2000) in Mansfield on Monday. Slayer, Slipknot, Hatebreed, and God Forbid play a day-off gig at Augusta Civic Center (207-626-2400) in Maine on Sunday.

A former bandmate of Jim Jarmusch and Luc Sante, singer-songwriter Phil Kline has fashioned an ingenious suite of protest music using, as its lyrical source material, such found prose as the speeches of Donald Rumsfeld and the poems inscribed by Vietnam-era GIs on their cigarette lighters. He’ll perform "Zippo Songs: Airs of War and Lunacy" on Saturday at Mass MoCA (413-662-2111) in North Adams.