In the end, glam is more exciting

Recently asked what the word "authenticity" meant to her, Lady Gaga - the last major pop star to emerge during the decade we have just departed - tried her best, at first.

"Integrity, intention," she said, furrowing her neatly plucked brow.

Then she gave up the pretence.

"I can say this . . . to you all day," she harrumphed.

"It's not gonna reap anything."

She's right.

Of all the aspects of pop that went into fatal mutation mode in recent years, the cult of authenticity was hit perhaps the hardest.

The advent of downloading wrecked the music industry as we've known it, and along with many jobs and old-fashioned rock star dreams, core assumptions about what makes music meaningful have been changing too.

A major one has to do with what we think is most real, most able to embody sincere and powerful emotions.

We have come a long way from the '90s, a period with the commercial triumph of credibility-obsessed subcultures such as indie rock and hip-hop, and the rise of artists like Kurt Cobain and Tupac Shakur, who were undone, partly, by inner conflicts about crossing over and selling out.

Other important figures, including Lilith Fair leader Sarah McLachlan, R&B-hip-hop fusion pioneer Lauryn Hill and country maverick Garth Brooks, also sought to change the mainstream in the 1990s but were ambivalent, and retreated artistically once they did so.

Authenticity was a major concern for these standard-bearers.

But by the end of the '90s, that value was fading.

The princess Lolitas and the boy bands brought back the dressing-for-prom spirit of teeny-bop, and Beyonce, still in Destiny's Child, began formulating her plan to reinvent R&B as a wicked combination of hip-hop boasting and Broadway-style pizazz.

The most fascinating personalities of this new era would never present themselves as unwashed or genuinely unplugged.

They're show people who are able to dance, crack jokes and work all the knobs that power their multimedia extravaganzas.

Eminem and Britney Spears, will.i.am and Kanye West, M. I. A. and OutKast, Rihanna and Lil Wayne: in nearly every niche, millennial artists have shown a marked preference for artifice over raw expression, costume and theatrics over plain presentation and foregrounding the tools they use to make music over pretending that it all comes "naturally".

Let's take two not-so-obvious examples.

Eminem was the best-selling album artist of the past decade.

Who's more serious than that tortured rapper?

But recall his emergence at the end of the last century.

The Real Slim Shady was a comedian whose very act was based on playing around with the idea that, as a white guy meddling in hip-hop, he couldn't be "real".

Then there's Radiohead.

It's impossible to find a more earnest embodiment of that central unit of authentic rock, the band, today.

Yet no matter how scruffy the image of Thom Yorke and company, Radiohead's music runs on the illusions and nightmares of the post-millennial world.

Using club beats and the fragmented compositional structures of contemporary classical music, Radiohead writes little operas for paranoid androids and mutant fishes in the information stream. As the decade ends, pop grows ever more bent on making inauthenticity ring true.

Every indie kid seems to be writing a musical or sewing her own superheroine cape.

Billie Joe Armstrong, still committed to mascara, kept Green Day alive by becoming a rock opera librettist.

Adam Lambert turned American Idol glam, and great, again.

And then there was Glee, the first real musical to work as an American television show, reminding us all that even life's most daunting problems can be lightened, if not solved, by a choral version of classic rock.

There are obvious reasons for this abandonment of solid-feeling values - not just "authenticity" but also "purity" and "rawness".

Novelty and sonic shine are primary values in a music business powered by catchy ringtones and downloads instead of albums.

Technology also has profoundly changed the way music is made; kids are learning how to play synthesizers before they bother with guitars, and tools such as Auto-Tune and Pro Tools have made "natural" sounds passe.

But even as the dire economics of music-making (and, by the way, music journalism) call for a lament, I celebrate the return of glitter and weirdness and fakery in pop.

It's opening up the doors to those who didn't fit more constrictive paradigms of authenticity: more women, more gay and lesbian faces, more multiracial and international voices.

In general, it's making for a fuller reflection of life in our fragmented, hyper-accelerated time of struggle. Pop today might seem like a big charade, but it's teasing out deeper truths.

Authenticity's bound to make a comeback; after all, Brooks just came out of retirement (not that he doesn't have a showman's flair!) and Lilith Fair returns next spring.

But after the decade just gone, even the most sincere expressions of self will have to be multiple and complicated.

We've finally all learned the lesson of the disco prophet Sylvester: only by admitting that nothing is straightforward can we feel Mighty Real.