MANSFIELD, Mass. -- I don't reckon there are a whole lot of Iraq-war supporters among the fans of Crosby, Stills, Nash and Young, but if there were any at the Tweeter Center here last night they probably left pretty upset.

As advertised, the CSNY show was a no-holds-barred musical rejection of the war in Iraq and the people who created it. There was virtually no talking from the stage, but the music left no ambiguities. And if you couldn't hear the lyrics, the peace signs and Iraq-war footage projected behind the band got the point across, too.

When it comes to musical unambiguity, Neil Young's your man. And on this night, CSNY was a good cop-bad cop act, with David Crosby and Graham Nash supplying the sweet harmonies to get across their highly poetic '60s and '60s-influenced odes to peace, love and understanding, then Young (occasionally with the aid of Stephen Stills) going for the throat.

And in those moments, it was riveting, for all Young's occasional jejune lyrics. The hard fact is, Crosby, Stills and Nash needed Young. Young was helped by Crosby, Stills and Nash, but he didn't need them. Outwardly, he seems the least taken by the possibilities of What Rock Can Accomplish, yet that may be exactly why he accomplishes more, certainly why he rocks harder.

The first set of the three-hour show included virtually all of Young's recent explicit Living With War album, including the deceptively jangly "Flags of Freedom" opening the show and the rocking "Families" (including Iraq battle footage projected behind the band), which should've ended the set but instead yielded the honor to the meandering "Deja Vu." Attempts by the rest of the group to get a word in, such as "Almost Cut My Hair" and "Immigration Man," merely broke the momentum, and after the title track from Living With War the rout was on.

The group's trademark narcotic harmonies are intact, and all the stronger for having Young back in the fold. As always with CSNY, great voices like those make it hard to resist the temptation to la-la-la your way through a few songs, and unfortunately they fell off the edge a few times.

Stills still has his impressive guitar skills, though his relatively clean inside-the-box Stratocaster sound was often upstaged by the loony stabs from Young's distorted Les Paul, which he often played as if wrestling a steer.

The second set started with the insipid "Helplessly Hoping" and "Our House," then went into a long section devoted to the quartet playing in smaller configurations, particularly Nash and Crosby on just-so versions of "Guinnevere" and "Milky Way Tonight" (from Crosby and Nash's 2004 self-titled album).

Young cut through the excess poetry with a spare version of "Only Love Can Break a Heart," and reminded everyone of the focus of the show with a guitar-bass-drums version of the heartbreaking "Roger and Out," a war-buddy tribute from Living With War (both with backing-vocal help from Crosby and Nash). And Stills and Young made an appealingly shaggy duo on Stills's "Treetop Flyer."

Still, the show was losing momentum ("Teach Your Children," natch) until the chanting "Find the Cost of Freedom," which led directly into the jaunty "Let's Impeach the President," from Living With War and the old Buffalo Springfield chestnut "For What It's Worth."

An a cappella "What Are Their Names?," from Crosby's 1971 solo album If I Could Remember My Name, was powerful for its spareness, and it nicely set up a corrosive version of Young's "Rockin' in the Free World." The encore "Woodstock" was nice, though not thoroughly necessary.