In the last days of the Beatles, as things were starting to come apart, the band formed a record label called Zapple. The idea -- or lark, really -- was to record experimental music and spoken word, starting with the poets who had become the band's friends. The orbits of rock and poetry were pushing at each other: musicians like Bob Dylan or Joni Mitchell were starting to claim the mantle of poets, and the Beats were hanging with rock stars, enjoying a small piece of the reflected adulation. Why not merge the two in one grand goof? It got off to a promising start. Allen Ginsberg, Lawrence Ferlinghetti, Richard Brautigan and Charles Olson put themselves on tape, and Michael McClure, the West Coast poet, volunteered to play his autoharp -- a gift from Bob Dylan -- behind the verses of a Hell's Angel named Freewheelin' Frank. But Zapple folded after just two albums, and within a year, the Beatles disbanded.

Paul McCartney, who had been the push behind Zapple, finally invoked his own poetic license earlier this year with the publication of "Blackbird Singing: Poems and Lyrics 1965-1989." Always considered less writerly than John Lennon, McCartney joins a procession of pop stars who have loosed their song lyrics on the poetry sections of bookstores in recent years. Bob Dylan, Joni Mitchell, Leonard Cohen, Lou Reed, Patti Smith, Suzanne Vega and Robert Hunter of the Grateful Dead have all published big collections of their song lyrics and other writings. A volume of Richard Hell's work is due out in the fall. Henry Rollins, Jewel and Tupac Shakur have published volumes of their poetry.

What does it mean for a select group of pop songwriters, in the wane of their careers, to be repositioned as poets? Norman Mailer once snorted that "if Dylan's a poet, I'm a basketball player." The books are a serious publishing endeavor but an odd one, seeking not an audience or even a lasting imprint -- the musicians already have that -- but a claim to legitimacy. They revive the old question of how rock or rap lyrics, removed from the roar and theater of the music, fare as poetry. On the cold black and white of the page, do they still sing?

The worst of the fighting has long been settled. Poetry is thriving -- on the Internet, in slams and public readings -- but for most of us, song lyrics now do the work of modern verse: they organize the truths that rattle around in our skulls. As universities trim their studies of Coleridge or Eliot, English majors read Dylan or Tupac for credit. The lyrics and their supporters have won, if only for outlasting their critics. Of course the lyrics are poetry. No populist definition could exclude the lyrics of rock songs, any more than it could exclude the songs of Sappho or the "hey nonny nonny" nonsense of Shakespeare; any high-culture guardians who would exclude rock have lost the authority to do so. The books of lyrics are the spoils of victory -- not an aspirant's claim but a victory lap.

But the value of this victory is questionable. After living so long under these songs' caterwauling sway, I recently spent a month inside the ruminative pages of the printed lyrics, without the alimentary boost of the music. It is a quiet neighborhood, filled with nice finds: the mature lyricism of later Joni Mitchell songs, the economy McCartney hewed to in the Beatles. Yet these seem like dry satisfactions. There are some fine verses in these books, but the power and poetry forged by McCartney, Mitchell and the rest lie in a far more complicated and scurrilous set of connections.

In a brilliant afternoon in the spring, Bob Holman, a poet and believer, piled the books of lyrics on the desk of his TriBeCa loft. An original member of the raucous Nuyorican Poets Cafe on the Lower East Side, he has done more than anyone to restore the rattle and dissonance to poetry, the sweaty ambition of performance and rant. He wears rectangular tortoise-shell glasses and has a shock of hair cresting from the top of his head, as if it's pulling him up from above. He jabbed a finger happily at a bridge in McCartney's "When I'm 64":

You'll be older too,
And if you say the word -
I could stay with you.

It was a formal element, a haiku -- well, almost -- illustrating what Holman thought was wrong with drawing a line between poems and songs, isolating poetry from the stream of popular culture. "We make these distinctions so we have something to talk about other than the poems themselves," he said. He started piling up a second round of poetry books -- pamphlets called chapbooks that are sold at slams. "These people are writing great rock 'n' roll poetry," he said, spitting the "hair-flinging anarchy" of rock 'n' roll. He meant this as a compliment, but it was also a recognition of how poetry and pop music have shifted their public roles in the last few decades: how poets are now happy to seek legitimacy in the vulgar swagger of rockers rather than the other way around. The alternative is the quiet cloister of the academy.

Song lyrics have no obligation to work as poetry. Though poetry began in song (lyric poems, for example, were set to the lyre), by now, the two serve different needs. To oversimplify, poems shape the public language -- words, meter, what have you -- to reveal interior truths. Songs, by contrast, have to unite audiences in collective truths. Great lyrics, even fancy ones, do not necessarily aspire to poetry. For example, John Lennon's song "Give Peace a Chance" scans neatly:

Ev'rybody's talking about
Bagism, Shagism, Dragism, Madism,
Ragism, Tagism
This-ism,that-ism, is-m, is-m, is-m.
All we are saying is give peace a chance

But the song's yearnings and remedies are all exterior, and its persuasion lies in melody and timbre; it succeeds as song, not as verse. This is not a lesser victory, just a different one. As Yeats wrote, "We make out of the quarrel with others, rhetoric, but of the quarrel with ourselves, poetry."

Yet nothing prevents songs from taking on this other, interior quarrel. If poetry is, as Leonard Cohen contends, a verdict and not an intention, rock has long extended itself as an opportunity, a soapbox for poets and pseuds. Lou Reed studied with Delmore Schwartz.

Cohen and Patti Smith were published poets well before they recorded songs. Richard Hell, then Richard Meyers, ran away from home at age 17 to come to New York and be a poet -- a romantic journey, tied as much to vices as verses. "It's interesting how you put that, 'The romance of poetry,' taking for granted that it's about a whole sexy way of life," Hell said in a recent e-mail exchange. As a teenager, he idolized Dylan Thomas; he slid from poetry to what became punk rock, gaining and losing something along the way. "I thought I'd have fun bringing things I'd learned reading and writing poems into music lyrics, but I ended up mostly writing just way more spicy versions of the classic lyric styles."

In the quiet of print, rock lyrics are often less than meets the ear. Rock has always found meaning in nonsense, whether the exuberant whoop of Little Richard's "wop bop a loo bop," or the portentous non sequiturs of the alternative band Pavement:

Life is a forklift.
Now my mouth is a forklift,
This I ask:
that you serve as a forklift too.

These puzzlements are diffusely utopian: they promise the existence of another world in which life can be anything and all confusions melt away. Salman Rushdie, in his novel "The Ground Beneath Her Feet," writes of this vision: "Song shows us a world that is worthy of our yearning, it shows us our selves as they might be, if we were worthy of the world."

The embrace of nonsense and non sequiturs is an inheritance from rural folk music and the blues, which use absurdism to face a capriciously hard world. Dylan adapted this trope for a rock 'n' roll world grappling with Vietnam and the destruction of the civil rights heroes. Applying old truths to a fiercely modern form, he conjured anachronistic landscapes of hard rain and darkness at the break of noon, biblical justice and sorrows. Songs like "Desolation Row" poked at truths using language that was rambling, funny and resolutely poetic, whether sung or sprawled across the pages of Dylan's "Lyrics, 1962-1985":

They're selling postcards of the hanging They're painting the passports brown
The beauty parlor is filled with sailors
The circus is in town
Here comes the blind commissioner
They've got him in a trance
One hand is tied to the tightrope walker
The other is in his pants

This was a literary play, evoking one vision of desolation to critique or exorcise another. You didn't have to follow all his allusions; Dylan's power lay in creating mystery, not resolving it. Audiences that once screamed through Beatles shows hung rapt on his words. And after Dylan, it is fair to say, the deluge.

But the import of rock songs often lies in the gaps between the words, inviting the guesswork and reflection and temporary epiphany that are the richest part of listening. The real lyrics to "Louie, Louie," for example, could never signify like the rumor and innuendo. And unlike the words of Cole Porter or Stephen Sondheim or the other pop or cabaret writers compiled in the recent book "Reading Lyrics," which deliver the same message whether sung or read, the rock songs need the blur of the music to fill in the meaning. Even vacant rock songs -- say, "Pretty Vacant" by the Sex Pistols -- promise not a vacuity of meaning but a surfeit. It has been a tenet of the rock era that those three-minute songs, pored over by their adherents, carry deeper truths than the institutions around them. This may be a vanity, but it has been a powerful one. The words are just the way in. As Pete Townsend of the Who once said, discussing MTV, "You can speak a language there where nothing you say needs to make sense, but everyone understands you anyway."

The persistence of this shared meaning points to one of the poetic limits of song lyrics. They communicate collectively; they preach to the in crowd. The words to songs, however idiosyncratic, do not direct us to recognize an intelligence independent from and outside our own. Instead, they give novel shape to our points of agreement, what Richard Hell called "the classic lyric styles." Dylan's "Ballad of a Thin Man," for example, about the hopelessly square Mr. Jones, would be lost on its central character. Decades later, when Dylan began writing as a born-again Christian, hectoring his audience -- which is to say, moving away from any points of agreement -- he ceased to communicate as a songwriter. Poetry is not obliged to these communal ties.

Rock lyrics are by nature overheated and fragmented; they generate more good lines than coherent works. Some of the most compelling believe in revelation or transcendence but stop short of trying to show it (this is perhaps low art's privilege: to defer to a higher art for the details). Lou Reed's "Some Kinda Love," for example, hints at revelation through sexual transgression, walking only as far as the edge without looking over:

Put jelly on your shoulder
Let's do what you fear most
That from which you recoil
But still makes your eyes moist

The lyrics, the jelly, get you halfway there. The music -- Reed's flinty voice, the erotic curl of the guitar notes -- suggests enough of the rest.

Many of these evocative fragments do not seem so pretty on the page. As poems, even good song lyrics often feel beholden to easy rhymes or predictable formulas. Taken out of context, these songwriting conventions often feel exposed and mannered. Music is a soft lyric's best friend, and a lot of the verses here can use the companionship. But there are also some revelations on the pages. Leonard Cohen, who published his first book of poetry a decade before his first album, reads as darkly funny on the page, a quiet smolder in a neatly tailored suit. In a typically corrosive twist on the cliche of the tormented artist, he writes,

I said to Hank Williams, "How lonely does it get?"
Hank Williams hasn't answered yet
but I hear him coughing all night long
a hundred floors above me in the tower of song.

The biggest surprises are McCartney's. John Lennon's 1964 book "In His Own Write" bills its author as "The Writing Beatle!" "Blackbird Singing" is McCartney's revenge. Instead of mooning about poetic stuff like misty weather and limpid eyes or reaching for the grand statements favored by Lennon, McCartney at his best is all business, compact and plain-spoken. His characters have names, like Lovely Rita or Father Mackenzie, and perform bold, funny actions: they came in through the bathroom window or, like Joan in "Maxwell's Silver Hammer," they got "quizzical, studied pataphysical/Science in the home," a reference to the Dadaist playwright Alfred Jarry's science of imaginary solutions. His "Eleanor Rigby," which I find maudlin as a song, shows its hardness on the page, as flawless a poem as rock has produced:

Father Mackenzie,
Wiping the dirt from his hands as he walks from the grave.
No one was saved.

McCartney's lyrics are taut and polished; it's nice to have the leisure to crack them.

Even on the page, the lyrics do not escape the accidents and textures of performance. Robert Pinsky, the former poet laureate, has long argued for the centrality of voice in poetry, whether written or sung. "Poetry, for me, is written with the poet's voice and intended for the reader's voice," he said. "The point for me is not 'the page.' Rather, the test is how beautiful or exciting the language sounds when it is spoken. Great poetry sounds great in any interested reader's voice." Fans constantly give their voice to the lyrics lodged in their heads; the books of lyrics are formal invitations to let loose -- a primal karaoke. Pinsky welcomes the books with the competitive warmth of a poet at a slam. "The cheese department," he said, "should offer many things between Velveeta and an exquisite goat cheese."

So far, publishers seem less eager to enshrine the lyrics of hip-hop, which on record often move too quickly to be counted. Except among the truly committed, there is not much place in the culture now for all-night bullcrit sessions to peel the layers of meaning and nonsense in the lyrics of the Notorious B.I.G. or Eminem. Yet the era's most beguiling, word-drunk songwriting has come from writers like Tupac Shakur, who was killed in 1996. Lauryn Hill, an Ivy Leaguer from New Jersey, laced her rap with a running commentary on how to read her:

I treat this like my thesis
Well-written topic
Broken down into pieces
I introduce then produce
Words so profuse
It's abuse how I juice up this beat
Like I'm deuce

Like the lyricists of the 1960's, hip-hoppers write against a backdrop of social crisis, often exaggerating it with mordant humor. In the early days of N.W.A., Ice Cube introduced himself,

I'm expressing with my full capabilities,
And now I'm living in correctional facilities

This is another wry take on the tortured artist as outlaw, isolated not in Leonard Cohen's tower of song but in Los Angeles's county blues. Rappers have often defended the excessive violence, sexuality, materialism and psychopathology in some lyrics as a kind of journalism, unpretty dispatches from the front. But with their vivid sensationalism and the creative chaos of their language, they function much better as poetry than journalism. The words can be redundant or contradictory -- or throwaway, like the formulas Homer used to make his lines scan. The Notorious B.I.G. raps,

My life is played out like a Jherri Curl,
I'm ready to die

How to reconcile the radically divergent tones of the two lines, the dirty-dozens humor of the first, the bleak fatalism of the second? Except maybe to recognize both as survival postures and B.I.G. as running through the various cultural currents flooding his life. The poetry lies in the sum of the two lines, not in their reduction.

If rock or rap lyrics have usurped the role of poetry, it's not very likely that many know enough to miss it. A few years ago, an English professor named David Pichaske asked several groups of people to identify a poem or line from the works of 25 recent Pulitzer Prize-winning poets. Then he asked again, using 25 popular songwriters. The results were exactly as you would expect. The books of lyrics function as souvenirs of this ascendancy.

The collected writings of, say, Patti Smith may not leap off the shelf, but they mark out her place in our public and private lives. For fans squinting toward middle age with their copies of her album "Horses," the existence of such a book can mean that we haven't outgrown her triumphal squall, even if we're no longer braving the sodden toilets of CBGB to get close to it. If you wanted to put a value on this glow, you might consider Jewel's publishing advance for "A Night Without Armor," reported to be more than $1 million, compared with the usual $10,000 to $20,000 for books by name poets. The book's introduction, which cites Jewel's influences, misspells Bukowski.

Rock music has long settled into genteel, adult ambitions. But if the books of song lyrics are intended to breach the canon, they are too late; that battle is over. Writers like Dylan, McCartney, Lennon, Mitchell, Tupac and the rest triumphed by embedding their poetic intelligence in the rhythm and noise and commerce that make up our modern lives. These books distill one part of that intelligence, but they are, as Pete Seeger once described the printed lyrics of folk songs, like a photograph of a bird in flight. They capture the verbs and nouns, but not the power that upended the rules of gravity that existed before.