American Idol tops an estimated 30.1 million rating so far in the most watched prime-time show TV season debut on Tuesday night.

The rate is down 10 percent from the 33.4 million who watched the season opener of the Fox network show in 2008, from 37.4 million who watched the 2007 debut represents the series' high point, said the Nielsen Media Research.

The eighth season of American Idol came roaring out of our TV sets as new judge Kara DioGuardi made her television debut and Contestant Katrina Darrell, 20, decided to wear a barely-there bikini as she auditioned in Phoenix.

Kara DioGuardi has plenty of fans who may not even know they are. She's one of the most commercially savvy songwriters in current female pop.

She has penned hits for Christina Aguilera, Gwen Stefani, Hilary Duff, Ashlee Simpson and more. Not coincidentally, she also has penned songs for former AI winners David Cook, Carrie Underwood and Kelly Clarkson.

The night's other successes are Michael Sarver, 27, who works as a roughneck on an oil rig, Emily Wynne-Hughes, 21, a pink-haired, tattooed and pierced rocker, and 23-year-old Scott MacIntyre, who can only see two degrees of tunnel vision.