BY STEVEN ROSEN

If Leonard Cohen, now 74, intends to retire from performing after his current tour, he couldn't have picked a better venue for his final North American show. Colorado's outdoor Red Rocks Amphitheatre, built into the foothills just west of Denver, is breathtaking enough to make you patriotically sing out "America the Beautiful" even at an otherwise-rowdy Sex Pistols show. (The reunited Pistols played there a decade or so ago.)

And with a crowd a bit less than the venue's 9,450 capacity cheering along during Cohen's 3+-hour show, as spotlights illuminated the nearby rock walls and a cooling late-night wind blew against a perfectly clear night, you felt democracy - or nirvana - really was coming to the U.S.A. ("Democracy" was one of Cohen's several encores, and you could hear the collective sigh at the line about the "battered heart of Chevrolet.")

But based on this show, don't expect Cohen to give up the concert business after the upcoming European swing of the tour. True, he waited 15 years between this tour and the last, but he also proved he gets better with age. There's no reason he, like such mature song stylists as Charles Aznavour, Elaine Stritch or Jimmy Scott, can't keep going. He certainly has the stamina for it, skipping like a kid on and off the Red Rocks stage between sets and encores.

Like so many singer-songwriters (and also garage-band rockers) liberated by Bob Dylan's success in the 1960s, Cohen was able to get a recording contract - and a devoted following - despite not being blessed with a "perfect" voice. Words and attitude mattered far more. Cohen's voice was growly and low-register, sometimes a forlorn moan. But he was already an acclaimed Canadian poet, so people paid attention to the words - romantic but never maudlin. Plus, he was a great songwriter, having a knack for memorable minor-key melodies and verses connected by gorgeously dramatic bridges, as on "Tower of Song."

Boomer artists like Cohen have been served well by time - rather, time is irrelevant to appreciating them. (It's truer for men than women, but this too is changing.) Unlike, say, Bobby Rydell or Bobby Vee, nobody cares if they "lose their voices" as they get old. They never had their voices, in the traditional pop sense. All that matters is, do they still care?

And, God, did Leonard Cohen ever care at Red Rocks! Dressed in a trim dark suit, often wearing a black hat, he frequently fell to one knee at the start of song, to emphasize the depth from which he was drawing out his vocals. And that bass growl of his was forceful and impassioned, full of clarity and musicality as he hit even the lowest notes.

With a supporting six-piece band whose members also wore dark clothes, Cohen stood or walked on stage admiring the music his entourage made. The arrangements could flaunt tight jazz-rock drive, but also had a European/Latin flavor - Javier Mas' extensive use of bandurria and 12-string guitar especially had echoes of Spanish flamenco as well as Argentine tango.

While the show slightly emphasized Cohen's work since I'm Your Man, it was generous with earlier material, including "Bird on the Wire," "The Partisan" and "Famous Blue Raincoat." "Hallelujah," which at this point risks overexposure, was given an ever-so-slight new arrangement that gave it just the right push, the lilt, to get past familiarity and seem new. He also played guitar for one of his oldest and most folk-oriented songs, "Suzanne."

The crowd tittered slightly at the "giving me head" line in "Chelsea Hotel 2," but cheered strongly at the song's subsequent "we are ugly but we have the music." That self-effacing lyric and the response seem to hold a key to the long-lasting success of Cohen. In a world of commercial pop, he shouldn't be this successful as a recording artist. He's the underdog made good - because he, like his audience, is so touched by his music. (When he says "ugly," it means - I think - "real."  After all, he remains a dapper and handsome gentleman into his 70s.)

While he relied on his three female back-up singers - longtime collaborator Sharon Robinson and sisters Charlie and Hatty Webb - to cushion the songs with their harmonies, he only rarely sat one out vocally. For instance, unlike on his 1988 tour, he joined in on the urgent, soaring chorus of "First We Take Manhattan," one of his most rock-like songs. And when he let them have a solo turn - Robinson on "Boogie Street"; the Webb sisters on a haunting version of "If It Be Your Will" - it was a chance for him to appreciate their beauty, not hide and rest.

The crowd was older, yet quite a few young people were present. A young woman next to me - maybe in her twenties - seemed to dreamily utter "beautiful" at each song and proclaimed the show "magical" when it was over. A man whose first name was "Cohen" - after the singer - and his wife brought their two young children to see his namesake.

While writing this review, I watched a PBS documentary on Neil Young in which he stressed the necessity of his orneriness, at the cost of kindness, as a way to remain musically relevant into late middle age. There is much to be said for this "do not go gentle into that good night" school of rock stardom - Bob Dylan, Van Morrison and Tom Waits as well as Young have all seemed to benefit from it.

But Cohen, who is older than any of them and has spent years studying Zen, has always emphasized grace and munificence, and he (and his music) are the better for it. After bringing as much of his tour crew as possible on stage for a final goodbye (after "I'm Trying to Leave You"), he left with a final statement that seemed like a benediction. "May you be surrounded by friends and family, and if this is not your lot may the blessings find you in your solitude."

In that regard, his concert was a blessing.