The last of the great 1970s bands—Crosby, Stills, and Nash—gave it their all for three hours at the Orpheum Monday, proving that it’s still possible to rock if your hair is white and most of the drugs—other than glucosamine and Celebrex— have been flushed from your system.

These days, David Crosby doesn’t look like a rock god; with his white mane and Wilford Brimley mustache he looks more like God Himself, if God decided to bag the heaven gig and start a band. He and Graham Nash were dressed in identical black shirts slit lower than Stephen Stills apparently cared to go. Instead, Stills went rock-star-dad casual: jeans and a blue polo shirt, accessorized with eight or ten different guitars.

It’s a delicate balance. Concerts like these are all about evoking the past without actually succumbing to it. With all the screaming and whistling that greets them when they walk onstage, CSN could call this “The Unconditional Love Tour.”  But for the group itself, the challenge is giving the fans what they want to hear—CSN’s greatest hits—without conceding that their best days are behind them, or that their signature brand of old-school sentimental liberalism is irrelevant.

Luckily for CSN fans, a trained set of vocal chords doesn’t betray the ravages of time quite as much as other parts of the body. All three can still sing with the power, conviction, and nuance that made them great in the first place, even if they do choose to harmonize in a lower key every now and then. Both Crosby and Nash sound like their voices have been preserved in formaldehyde, and Stills’s voice—though hoarser and croakier, as if the decades have etched crags and eddies in his throat that make it more difficult to get the words out—is more emotionally evocative than ever.

Not many bands can roll out the hits one after the other like CSN. On Monday night, they came in waves—“Carry On,” “Long Time Gone,” “Just a Song Before I Go,” “Southern Cross,” “Marrakesh Express,” “Love the One Your With,” “Helplessly Hoping”—with interludes of new material, obscure Dylan tunes (“Girl From the North Country”), and a few protest songs for the 21^st century. Graham Nash sang a song called “Almost Gone,” about Bradley Manning, the U.S. soldier currently awaiting trial for passing classified documents to Wikileaks. “What I did was blow the whistle and the games began,” goes the song’s refrain. “But I did my duty to my country first, that’s what they taught me as a man.” Nash also dedicated “In Your Name,” a song off his Reflections album, to the victims of the shooting at the Sikh mosque in Wisconsin on Sunday. “Lord, can you stop all this killing in your name?” goes that song’s chorus. Hard to get more relevant than that—or less subtle.

Polemics aside, the band sounds great on this tour, in part because their five-piece backup band is so stellar, and because Steven Stills can still rip off a mean guitar solo. Vocally, the band wasn’t seamless—there were are few hiccups here and there—but they did have the guts to dedicate the first half of the second set to songs sung a capella or with the backing of only one acoustic guitar. Crosby and Nash used Guinnevere to cast a modal spell over the entire audience, and Crosby presented an entirely new song (which he said he’d only performed twice), an oddly meandering but heartfelt lament for prostitutes and (he imagines) their necessary lack of an inner life.

The band can jam, too. Stills’s stabbing, stinging guitar solo on Buffalo Springfield’s Bluebird made me want to go get tickets for the BS reunion tour, which was supposed to happen this year but was postponed. And the three separate jams on Wooden Ships closed the second set with pretty much everyone up on their feet and cheering.

The only disappointment of the evening was not getting a “Suite: Judy Blue
Eyes” for an encore. We got Teach Your Children, which was a nice sing-along, but CSN has done Suite as the final encore at virtually every stop on this tour. Why they didn’t do it last night is anyone’s guess. I suspect they’re saving it for the next tour, after David Crosby has his meeting with God and they decide who gets to hold the guitar.