When the Americana Music Association held its first-ever awards show in Nashville last month, the surprise guest was Johnny Cash. The 70-year-old icon didn’t look well, but he was in good spirits, joking with his wife June Carter and speaking enthusiastically. Cash was on hand to receive the first Spirit of Americana Free Speech Award, and in his introduction, John Seigenthaler stressed Cash’s outspoken opposition to war and racism. So what did Cash do? He read his 1974 poem, “Ragged Old Flag,” a piece of verse so patriotic and sentimental that John Ashcroft would have smiled at it.

It was an odd choice for a room dominated by knee-jerk liberals. You could argue that it was as brave as singing an anti-war song in a roomful of conservatives, but I don’t think that thought ran through Cash’s mind. It was two days after the first anniversary of 9/11; I think he was feeling patriotic, so that’s what he talked about.

That’s why Johnny Cash remains so fascinating in this, his 48th year as a recording artist. He remains a bundle of contradictions—as maudlin as he is ruthless, as conformist as he is rebellious, as softhearted as he is tough-minded—and he allows those fragments of his personality to come flying out whenever they need to, career or reputation be damned.

He may have a cramped vocal range; he may have used the same handful of melodies and rhythms for every song he ever wrote; he may make great records or awful ones, but you’re always getting Johnny Cash, the son of an Arkansas sharecropper who never bothered with the niceties of irony and calculation. After all this time, that stubborn insistence on being himself is his music’s most appealing quality.

Of course, that hasn’t stopped people from trying to redefine him. For years Music Row tried to pass off this cantankerous eccentric as a conventional country superstar in the mode of Marty Robbins or Bill Anderson. In more recent years, producer Rick Rubin has tried to recast Cash as a black-clad, sexagenarian alt-rocker. Now the alt-country scene has claimed this flag-waving hit-maker as a founding father. Cash can assume any of these roles but is defined by none of them.

The famous photo of Cash giving someone the finger backstage has been reprinted so often that new fans think of the singer as the ultimate outlaw. Rubin has tried to reinforce that image with a series of stripped-down sessions that revive Cash’s old outsider songs and give him new ones to sing. The first of these albums, 1994’s American Recordings, featured moody readings of unexpected songs by Tom Waits, Loudon Wainwright, Leonard Cohen and ex-son-in-law Nick Lowe. That was impressive, but with each succeeding volume the series seems to harden into the sort of shtick that’s antithetical to Cash’s art.

The fourth volume in the series, the forthcoming The Man Comes Around (Lost Highway), is better than the third but weaker than the second and a far cry from the first. Sure, it’s easy to stir up media attention when you have Johnny Cash sing songs by Nine Inch Nails and Depeche Mode, but that doesn’t mean there will be a convincing connection between the earthy singer and the high-school-lit-magazine lyrics.

It’s not as if the album is a total loss. Cash connects with Sting’s “I Hung My Head,” John Lennon’s “In My Life” and the old cowboy song “The Streets of Laredo” in ways that do credit to both the singer and the material. Better yet, Cash sings four strong songs of his own. Best of all is the title track, “The Man Comes Around,” a new song that he based on the book of Revelation. The lyrics are as spooky and incomprehensible as that weirdest book of the Bible, and Cash’s melody and vocal evoke a time of unexpected, unexplainable catastrophes. A time like our own.

The oddest aspect of this new album is Rubin’s decision to record without drums or bass. If Cash’s unflinching presentation of self has been the crucial element in his music, that indomitability has been inseparable from the rhythm in his songs. That clickety-clack railroad beat has often been parodied, but few artists have ever created such an emphatic pulse with such a lean sound. The legendary Cash rhythm section—Marshall Grant on bass, W.S. Holland on drums, Cash on acoustic guitar, and either Luther Perkins or Bob Wootton on electric guitar—never took up much sonic space, but they provided the forward propulsion that made the vocals seem like such an inexorable force of nature.

That rhythm is what’s missing from The Man Comes Around, and that rhythm proves the biggest challenge for the artists who pay tribute to Cash on two new albums, Kindred Spirits: A Tribute to the Songs of Johnny Cash (Lucky Dog) and Dressed in Black: A Tribute to Johnny Cash (Dualtone). Kindred Spirits, overseen by Cash’s onetime sideman Marty Stuart, emphasizes Cash the songwriter, so the interpreters feel free to beef up Cash’s rhythm (as Bob Dylan does) or abandon it altogether (as Bruce Springsteen does). As a result, the disc suffers the tribute-disc curse—it varies so much in sound and quality that it sounds more like a random slice of Top 40 radio than a cohesive album.

Dressed in Black, by contrast, focuses on Cash the performer, and the arrangements have a consistency that gives the recording a welcome unity. Chuck Mead (of BR549) and Dave Roe (Cash’s longtime bass player) not only produced all 18 cuts, but also played rhythm guitar and bass. They’re not quite as special in these roles as Cash and Grant, but they deliver a respectable imitation, and when they hook up with a guitarist who understands Luther Perkins’ lean guitar fills as well as Redd Volkaert, Kenny Vaughan and Rosie Flores do, the results crackle.

Dressed in Black may have the better overall approach, but Kindred Spirits has the better singers. Cash is one of those rare vocalists you can identify after just two bars of music; Dylan, Springsteen, Steve Earle, Dwight Yoakam and Emmylou Harris also belong to that select group, and Kindred Spirits has them all. The disc hits some lows (Springsteen’s dreary reading of “Give My Love to Rose,” Keb’ Mo’s glib country-blues version of “Folsom Prison Blues,” Hank Williams Jr.’s self-aggrandizing bombast on “Big River”), but the album also hits some real peaks.

Little Richard brings out the latent boogie-woogie in “Get Rhythm,” and Dylan turns “Train of Love” into an outtake from “Love and Theft.” Steve Earle strikes just the right balance of rebellion and fatalism on the outlaw ballad “Hardin Wouldn’t Run.” Johnny’s daughter Rosanne Cash connects with the pulse of Dylan’s bassist Tony Garnier on a lovely chamber-pop reading of “I Still Miss Someone.” And Travis Tritt brings a soulfulness to “I Walk the Line” that Dale Watson never musters on his own version of the song, from Dressed in Black.

Rubin, Seigenthaler and the guests on the two tribute albums all offer their definitions of who Johnny Cash is, but in the end their interpretations slide like snow off the mountain-like reality of a man who can sing “Danny Boy” immediately after a murder ballad like “Sam Hall.”