The country-music boom no one talks about these days is the one from five or six years ago, when new blood entered Nashville for the first time in years. In a town as closed as Nashville, this gentle tremor was something akin to a creative watershed. There were young songwriters with rockbound literary pretensions, like Lyle Lovett and Nanci Griffith; high-concept oddballs like lang, and thorny young cusses like Dwight Yoakam and Steve Earle. None was pure country, but as the pop mainstream tightened, they became country by default. Nashville not only took them in, it celebrated them as a new generation of comers. Creatively, they were about the best thing that could happen to the music.

The current boom, measured as it is in uniform cowboy hats and multimillion album sales, has come largely at the expense of these acts. Except for Yoakam, most are now either forgotten or gone. Griffith left her record label’s country division for the pop company. Earle left, too; he might as well have fallen off the earth.

But the most talented defectors are Lovett, 34, and lang, 30, who used their outsider status to critique country traditions even as they exploited them for pathos. Lovett, whom lang once described as a man who “probably gets into ‘Eraserhead’ for free,” simply switched over to his label’s pop side. His wiseacre songwriting was always closer to Randy Newman than Merle Haggard anyway. “It was a function of marketing,” he said. “The record company found that the people buying my records weren’t from the mainstream of country fans.” But lang, an animal-rights activist who was all but run out of Nashville after she publicly took a stance against meat, has abandoned country music entirely. “A lot of the people that reacted really strongly,” she said, “were just waiting for a reason to say, ‘See, I knew she wasn’t country, and I knew we couldn’t trust her.’ I understand that they were protecting a traditionalist aspect of country music, and I was a challenge or a threat to that. But that was an indication to me that I would never be what I had to be to make it in country, [and] that my desire to move on was a good one.” She calls her new torch-music style “post-nuclear cabaret.”

The change has done them both good. Their new albums - Lovett’s “Joshua Judges Ruth” and lang’s “Ingenue” - are the best of their careers. “Ingenue” takes off from lang’s mournful version of Cole Porter’s " So in Love" for the 1990 " Red Hot + Blue" AIDS benefit album. “This is music that I listened to before anything,” she said. “I was raised on classical music and Mom’s and Dad’s show music, Broadway stuff. I didn’t start studying country until I was 21.” Supported by accordions, strings and conga drums, her voice floats through languid, airy songs of obsessional love: “Always someone marches brave/Here beneath my skin/Constant craving/Has always been.” Like all of her music, “Ingenue” toys with intimacy and artificiality, finding kitsch and passion in the same turn of phrase. Here the tension between the two voices feels more affecting than sportive, as if the true pop expression of love lies in the seam between the two.

“Joshua Judges Ruth,” said Lovett, is about “death in a lighthearted way.” The title comes from three consecutive books of the Old Testament, and the voice of the Gospel - both the language and the sound-permeates the songs. But Lovett repeatedly ducks the heavenly call. In one song, the narrator jumps up in church and yells, “To the Lord let praises be/ It’s time for dinner now, let’s go eat.” In another, he goes to a funeral and rejoices at seeing old friends. Lovett, a former journalism major, has always been clever; that’s his gift and his curse. The one country song here begins its refrain, “She’s leaving me,” just like a thousand country weepers before it, then tweaks the formula: “Because she really wants to.” But he’s best dropping a flat observation with unexpected acuity: “The cowboys down in Texas/They polish up their guns/And the look across the border/To learn the ways of love.” A man could wander for days on the and plains of these songs.

The two albums prove that there is life after Nashville. But for Nashville, the implications are troubling. The country boom, sparked by fans coming to the music for the first time, is beginning to resemble the traditionalist-jazz boom, in which the choice spots go to the performers who best conform to what a bunch of rock-and-roll refugees think a jazz act should be. This is one stamp of musically restless baby boomers: they reduce musical traditions to niche functions. Megasales or no megasales, that’s not a boom. That’s a slide into irrelevance.