The Mothers of Invention, "We're Only In It for the Money" (MGM-Verve, 1968)

Each year, the Library of Congress adds various blasts of sound to its National Recording Registry, works "that are culturally, historically or aesthetically important and/or inform or reflect life in the United States."

Among the Library's 50 selections for this year is an album that meets several of those criteria: "We're Only In It for the Money," the third release by the Mothers of Invention.

By 1968, the band led by composer-guitarist Frank Zappa had established a reputation for blending music and theater. Some of its onstage antics involving dolls, stuffed animals, whipped cream, overripe vegetables and sundry other props have become the stuff of legend.

Likewise, Zappa had been crafting the Mothers' records as concept pieces, usually focusing on the shortcomings of American society. The 1966 debut, "Freak Out!" (rock's first two-LP set), addresses such topics as boy-girl releationships, the Watts race riots and the travails of playing in a not-so-popular rock band; the follow-up, "Absolutely Free," contained more direct attacks on the establishment with such ditties as "Plastic People," "Status Back Baby," "America Drinks & Goes Home" and the epic "Brown Shoes Don't Make It."

During 1967, Zappa watched developments in the music scene with a wary eye, particularly observing what was happening in the Haight-Ashbury district of San Francisco. Attracted by its pronouncement in the media as some type of epicenter for a "Summer of Love," young people flocked into town, stretching its resources to the limit. Instead of a hippie Utopia, many of those folks found a scene plagued by pushers, scam artists and other nasty people.

The bad vibes gave Zappa the impetus for what generally is regarded, nearly four decades later, as his classic work. And that's saying a lot, given his prolific recording right up until his death in 1993.

"We're Only In It for the Money" was a complete departure from what listeners were used to hearing at the time. Tight editing - still done back then by taking a razor blade to recording tape - allowed an array of musical and spoken-word snippets to come at a dizzying pace; mid-song interruptions could be anything from an orchestral section to Mothers drummer Jimmy Carl Black calling himself "the Indian of the group" (which he actually was) to a cameo by Eric Clapton, who proclaims, "God, it's God, I see God."

Meanwhile, the Mothers were stuck for a lead singer during the recording of "We're Only In It for the Money," as Ray Collins recently had left the group. As a result, many of the vocals on the album are speeded up, causing a tone that reviewers have compared to the sounds of Munchkins.

Then there are the songs, a whopping 19 of 'em listed - although they're all segued together, so sometimes it's tough to tell where one ends and the other begins. Many of them, particularly on the first side of the original LP, address Zappa's take on the "flower power" lifestyle, or at least the flawed ideal of it: "Who Needs the Peace Corps?" contains a veritable instructional manual (cynically presented, of course) about how to effect the look and attitude of a hippie.

The song "Absolutely Free" (not to be confused with the album of the same name) states the goal of abandoning all responsibility, with a floating caveat inserted at a strategic point: "Flower power sucks!" And the ensuing "Flower Punk" takes the hippie concept to its logical conclusion: "Hey punk, where you goin' with those beads around your neck?/I'm goin' to the shrink so he can help me be a nervous wreck."

Some of the material is much darker, notably "Mom and Dad," which places a good bit of blame for a female hippie's predicament squarely on the shoulders of her parents. That song has gained notoriety for Zappa's prescient lyrics: "Mama, your child was killed in the park today, shot by the cops as she quietly lay." Those words were written mroe than two years before the National Guard went ballistic at Kent State.

The original Side Two offered some lighter fare, particularly the hilarious "Let's Make the Water Turn Black," which Zappa later revealed was based on the true foibles of some old buddies of his. It's all a bit creepy, as is the next tune, "The Idiot Bastard Son," about the rather nebulous fate of an abandoned child. "Take Your Clothes Off When You Dance," one of Zappa's most enduring melodies, offers a bit of optimism: "There will come a day when everybody that you know will be free to sing and dance and love."

The single from the album - disappearing without a trace, of course - was "Mother People," which Zappa also "performed" on an episode of "The Monkees" TV show, believe it or not. (The "performance" consisted of him dismantling a car while the song played in the background.) "Mother People" is a call for those who are different not to let other folks bother them, although it loses a bit of potency with the censors excising one key line that happens to be laced with profanity. The snippet in question does appear, recorded backward, as a short burst of sound titled "Hot Poop."

Zappa veers away from traditional concepts of music throughout the album, culminating with the closing piece, "The Chrome-Plated Megaphone of Destiny," which drew its inspiration from Kafka's "The Penal Colony." The montage of dissonant sounds melds into a section of laughter - the monotone laughter of the disturbed, which can be a chilling sound.

Finally, everything wraps up with a single piano key playing middle-C, the Mothers' response to the grand chord struck at the end of the Beatles' "Sgt. Pepper's Lonely Hearts Club Band."

That was appropriate, given the cover art for "We're Only In It for the Money." Zappa and Philadelphia-area artist Cal Schenkel contrived to put together an extremely effective parody of the Beatles' most famous album cover, with a vast collection of colorful characters, past and present, joining the members of the Mothers - who are attired in the finest women's frockery.

And they're dressed that way on a sendup of the inside cover, too, resulting in a very homely collection of transvestites-for-the-occasion.

To complicate matters, the Mothers' label, MGM-Verve, ended up releasing the album with the intended inside art as the outer cover, meaning shoppers in the record store were greeted by a big picture of ugly guys in dresses. Apparently, no one wanted to risk legal action by the Fab Four on account of the resemblance to "Sgt. Pepper's."

Despite its bizarre cover and content, "We're Only In It for the Money" peaked at No. 30 on the American charts, representing the best showing here by a Zappa project until "Apostrophe" cracked the Top 10 six years later. And it took a novelty like "Don't Eat Yellow Snow" to accomplish that.

And despite its ties to subject matters of long ago, "We're Only In It for the Money" has lost none of its effectiveness as a work of satire. While Frank Zappa continued to point a caustic finger at various segments of society throughout his remaining quarter-century, never again would he produce anything so cohesive.

As a document to "reflect life in the United States" during the late '60s, the album has earned its place in the National Recording Registry.