Coachella Day 3: Leave it to Bieber!

No, "Bieber fever" has not hit the Coachella Valley Music & Arts Festival, thankfully. But the teen-pop idol (whose first name alone, Justin, is enough to invoke hysteria among his young fans) did make a cameo appearance Sunday when he sat in with Chicago hip-hop upstar Chance the Rapper.

The two teamed up for Bieber's "Confident," the recorded version of which also features Chance.

The fact that Bieber was not booed off the stage or pelted with, well, something or other, demonstrates that the embattled star is indeed confident. It also underscores the evolution of Coachella, for better and worse, more than Bieber, whose desire for an image-change may also have prompted his cameo last month at the anual South By Southwest music conference in Austin.

The festival began in 1999 as a hipster's paradise, a marathon for music geeks and hardcore fans who embraced cult bands and disdained mainstream pop and rock with a passion. Coachella was a proving ground for the coolest of the cool, both on stage and in the audience. That may be why the festival took several years to break event, but its initial devotion to music over commercialism was admirable and was key to its uncompromising reputation.

But that was then and this is now, and what was once an underground sensation is now a magnet for Holywood celebs and the paparazzi who shadow their every move. Too, Coachella has featured an array of artists -- including Prince, Madonna, Jay Z and Paul McCartney -- who have filled stadiums. Accordingly, it has grown from a one-day event, to two days, three days, and (for the past few years) two consecutive three-day weekends, which sell-out even before the performance lineup is announced.

Coachella is so popular that the city of Indio now caps attendance each day at 99,000. Last year's edition of grossed a record $67 million, more than any other festival in history. That total seems likely to be surpassed this year.

If Bieber was looking to gain reflected glory and musical gravitas by being here, perhaps he succeeded, even if a one-song cameo is largely insignificant. That is, unless his well-publicized presence will prompt his mostly young fans to consider attending Coachella next year.

It's a notion that could have music hipsters everywhere shaking in their shoes and considering making alternate plans.