The only place where people can still come together over the Beatles is the marketplace. That they still do, almost 35 years past the Beatles' breakup and almost 25 years since the death of John Lennon, speaks to the tunefulness and timelessness of their music. It also presents a peculiar challenge to Capitol Records: How to celebrate the Beatles' music without seeming to simply exploit their catalogue?

The problem is most acute with Lennon, whose recordings -- originally on the Apple label, distributed in this country by Capitol -- have been pretty much exhausted by now, but who nonetheless is represented by two new releases, "Acoustic" and "Rock 'n' Roll."

"Acoustic" is pretty self-explanatory: It features acoustic versions (many of them home demos) of 16 of Lennon's post-Beatles songs; seven are appearing officially for the first time. They will appeal to Lennon/Beatles completists, songwriters interested in exploring a master's craft and musicians looking for new material: the CD booklet includes lyrics with chords and chord diagram charts (though more information about recording dates might have been useful as well).

The best-known songs are "Imagine" (in a version taken from a 1971 Apollo Theater concert) and the caustic "Working Class Hero," as well as primal-therapy tracks "Cold Turkey" (harrowing even without Lennon's weird warble), "My Mummy's Dead" (sounding like an ancient Appalachian plaint taped by Alan Lomax) and the angry "God," in which Lennon imbues classic '50s rock melody with postmodern nihilism, declaring: "God is a concept by which we measure our pain" before embarking on the litany of "I don't believe in I Ching, I don't believe in Bible, I don't believe in tarot . . . I don't believe in Elvis, I don't believe in Dylan, I don't believe in Beatles." Curiously, the demo has a different coda, with Lennon singing "I just believe in me"; in the version subsequently recorded by the Plastic Ono Band, the line goes "I just believe in me, Yoko and me."

For proof of that, listen to the ebullient Buddy Hollyesque "Dear Yoko," the charming "Love" and "Real Love" (suggesting that Paul McCartney's not the only former Beatle to write sappy, sentimental love songs) and "Watching the Wheels," Lennon's impassioned defense of his mid-'70s withdrawal from public life to serve as househusband and father to Sean Ono Lennon. Also of interest is Lennon's bluesy Hendrixian take on "Well Well Well" and "What You Got," a previously unreleased rockabilly romp. Sounding seriously dated: the anti-Brit "The Luck of the Irish" (the only track featuring the, er, distinctive vocals of Yoko Ono) and "John Sinclair," a paean to the then recently jailed founder of the White Panther Party (both from a 1971 Ann Arbor rally).

Turning to the Oldies

"Rock 'n' Roll" is a remixed and remastered version of the 1975 roots-rock album that would be Lennon's last before 1980's "Double Fantasy." Its original inspiration was legal, not musical: In 1973, Morris Levy, Chuck Berry's music publisher, threatened to sue Lennon, claiming that "Come Together," the Lennon-penned song from 1969's "Abbey Road" album, plagiarized Berry's 1956 song "You Can't Catch Me." Certainly Lennon's chorus closely echoes Berry's, and both songs feature the lyric "here comes old flat top." As part of an out-of-court settlement, Lennon agreed to record an oldies collection that would include three songs from Levy's catalogue, including "You Can't Catch Me."

Looking for a producer who could help him re-create the feel of classic rock-and-roll, Lennon turned to Phil Spector, whose Beatles-connected history was somewhat checkered. (McCartney waited decades to release a version of "Let It Be" stripped of Spector's production.) By the time he was drafted for "Rock 'n' Roll," Spector was operating with a heavy hand: Some sessions featured more than two dozen musicians, including a big, brassy horn section, but rather than being individualized and discrete, the 24 tracks used in the recordings were often left open to bleed into one another, resulting in a thick, echo-laden sound. Lennon decided that the Spector sessions had collapsed into "mania," once noting that it was "the first time I let an album out of my control since the first Beatles album." Spector disappeared with the masters; eventually only four of its tracks -- "You Can't Catch Me," "Sweet Little Sixteen," "Bony Moronie" and "Just Because" -- were deemed usable, and even those are turgid.

Two years later, Lennon completed the album on his own, recording several oldies in just four days with a much smaller band. But then, it was a labor of love, not law -- a way to honor and celebrate the music that had inspired Lennon and his fellow Beatles. Lennon was a rocker at heart, a fact underscored by Jurgen Vollmer's album cover shot of a leather-clad Lennon lurking on a Hamburg doorstep circa 1960.

At his best on taut rockers like Little Richard's "Rip It Up" and Buddy Holly's "Peggy Sue," Lennon is less convincing -- in fact, is quite sluggish -- on such R&B standards as "Stand by Me," "Do You Wanna Dance" and a medley of "Bring It On Home to Me/Send Me Some Lovin'." The new version of "Rock 'n' Roll" tacks on four bonus tracks, three of them alternate mixes of songs first featured on 1986's posthumous "Menlove Ave.," criticized at the time as barrel-scraping. Perhaps Lennon's awful version of Spector's "To Know Her Is to Love Her" was an act of revenge, not one of homage. The extra snippet of "Just Because" includes a Christmas greeting from Lennon to his former band mates, Yoko and the people of England. Capitol should consider compiling the Beatles' numerous holiday recordings made especially for their fan clubs.

On the other hand, Capitol has finally responded to American fans' desire to hear the Beatles albums -- at least their earliest ones -- the way they first heard them in the '60s. Next week brings "The Beatles: the Capitol Albums Vol. 1," a box set containing the four albums that introduced Beatlemania to America in 1964: "Meet the Beatles," "The Beatles Second Album," "Something New" and "Beatles '65."

When Capitol first issued the Beatles catalogue on CD in 1987, albums were standardized on a worldwide basis to the British versions. Eventually the early American albums, which had different titles and configurations and had last appeared on vinyl and cassette, were deleted. Now, American fans have the albums they grew up with, remastered from the original American masters to ensure that they sound as they did when first released. Each disc includes two versions of each song, one in mono, the other in "true" stereo, though seven tracks are "duophonic." That was the process Capitol created in the '60s using two mono channels that were equalized, compressed and reverbed, with instruments in one channel, vocals in the other channel -- ultra-primitive stereo that will sound comfortingly familiar to older fans.

This marks the first significant upgrade of the Beatles' earliest music since the advent of CDs. Each disc is housed in a miniature replica of the original album cover and the box includes a 48-page booklet with period pictures, news clips and charts. It's a heck of a way to cap the 40th anniversary of the British Invasion.

Two new releases, "Acoustic" and "Rock 'n' Roll," will likely appeal to John Lennon completists but perhaps not to connoisseurs.