Mirror Ball puts on the relationship. Though Young is clearly the dominant partner – it's his concept, after all, his songs and his album – it's Pearl Jam who ultimately end up determining the music's shape and feel, providing a level of input and energy that goes well beyond the normal purview of a backing band.

Just how much Pearl Jam bring to these songs can be gauged by comparing this "Act of Love" with the versions offered by Young and Crazy Horse in concerts earlier this year. At both the Rock & Roll Hall of Fame dinner, in New York, and the Voters for Choice concert in Washington, Crazy Horse's "Act of Love" was a lumbering behemoth, a slow-moving marathon of billowing guitar chords and rambling, snaky solos. It isn't only the abbreviated length (just less than five minutes) and comparative lack of guitar solos that set the Pearl Jam version apart, it's also the rhythmic vitality. Whereas Crazy Horse came across all muscle-bound and lugubrious, Pearl Jam have the lean, sinewy brawn of a champion welterweight, jabbing through the power-chord chorus with light-footed agility and ear-bruising assurance.

This isn't just a matter of musical style; there's almost a generational difference at work. Crazy Horse revel in the overamplified grandeur of acid-rock excess; Pearl Jam prefer the blunt beauty of punk's amphetamined minimalism. Young, though, is fascinated by both. And after spending much of Sleeps With Angels viewing the alterna-rock generation through the haze of Crazy Horse, here he spins the telescope around to see what hippiedom looks like through the lens of Pearl Jam.

To be honest, the view can be pretty funny. "Downtown," for instance, sends up the notion of '60s cool by cartoon hippies who head off to a place where "they dance the Charleston/And they do the limbo." But as much fun as Young and the band have with the image (as well as the tune's chooglin' three-chord groove), they don't overlook the era's most enduring strength: its music. "Jimi's playin' in the back room," sings Young, "Led Zeppelin's onstage." And although the music doesn't attempt to evoke that sound, it does convey its spirit.

They don't stop there, though. With "Peace and Love," Young and Pearl Jam cut to the heart of the '60s-'90s rift. After Young invokes the mystic ideal of finding "love in the people/Living in a sacred land," Eddie Vedder offers a sort of gener