Revealing the secrets of ‘American Idol’

"American Idol," which returns Jan. 13 for its eighth season, has generated billions of dollars in revenue, and been watched by millions of people, many of whom have questions about some behind-the-scenes details of the number-one show in the U.S.

Here's a look at some of the most frequently asked questions about the series. Note that some of our answers are based upon information from previous seasons; with "American Idol 8" making a number of changes this year, there's always the possibility that the show and contestants' experience might change.

Why does the show highlight so many bad singers during the audition rounds?
Because that's what made "American Idol" popular. While audiences eventually got drawn in by the competition between good singers, it's the terrible voices who first pulled in the viewers. Watching Simon Cowell criticize them was, at least in the early years, sometimes more entertaining than watching people who could actually sing.

Bad singers may seem like actors who are planted, and that's somewhat true. During the audition rounds, the judges don't show up until a few days in, after producers have screened and filtered through the massive group. Only the best and worst get called back and eventually get face time with the judges, so producers ensure those terrible people face Simon, Paula, Randy, and now Kara.

However, producers are planning to change this season, making the show more "aspirational" and spending less time on auditions. But you should still expect to see plenty of awful singers.

Why are auditioners shown singing songs they didn't perform in front of the judges?
Sometimes, audition episodes end with montages of (often bad) singers all performing the same song — and although they appear to be standing in front of the judges, they're singing a song we didn't see them perform earlier. It looks like they're in front of the judges because the backdrop is the same, and because editors insert shots of the judges' reactions. But those performances were recorded on an earlier day, before the judges showed up. Producers who are screening contestants ask them to all sing the same song to get footage for those montages.

What's the age limit for American Idol?
Contestants have to be 16 to 28 on the day of their audition, NOT on the first day of the show.

Thus, it's possible for 29-year-olds to be on the show if their birthday falls after their audition. The age was raised to 28 from 25 as of the show's fourth season.

What's the wild card round?
During the first three seasons, the judges were able to bring back eliminated contestants and advance them to the final rounds.

That's back for season eight, although the exact format isn't yet clear, and varied during those early seasons. Why does it matter?

One example: Clay Aiken. He was eliminated from the competition but came back thanks to the wild-card round, and became the show's most-successful runner-up.

How do contestants pick, arrange, and rehearse songs?
Very quickly, and with varying amounts of help. After the live results are revealed, they learn the next week's theme, and are given a sampling of songs on a CD. In the past they were able to choose songs not in that collection, but starting last year during the semi-final rounds, contestants were forced to select one of around 50 songs.

That ensured the producers would have permission to use the selected song, and ensured that contestants' choices wouldn't be too obscure. Contestants then work with professional musicians, from the show's vocal coach to the musician who creates arrangements. Musical director Ricky Minor and other musicians score the songs after listening to recordings of the contestants practicing.

Rehearsals take place throughout the weekend, culminating in three rehearsals the day of the performance show. Along the way, finalists do everything from picking out their clothes to filming those Ford commercials.

Where do contestants live?
In shared apartments close to the studio where "American Idol" is taped. Early on, they lived together in a mansion, but the apartments give them more personal space and privacy.

How are the finalists' wardrobes selected?
Contestants are given a clothing allowance, and shop with show stylists to select their wardrobes for the performance and results shows. While Fox hasn't released the exact amount in recent seasons, it was $450 a week in season three. Presumably it's increased since then.

How can I attend an "American Idol" live show in Hollywood?
By signing up and joining a wait list for the free tickets. Note that there is no seating. You have to stand the entire length of the show.

How do contestants afford to be on the show for more than three months? Do families get paid to take time off and be in the audience?
Like most reality shows, participants sacrifice in their day-to-day lives for a shot at fame or fortune on television.

Just as "Survivor" contestants leave their jobs (sometimes negotiating with their bosses to return after their seven or eight weeks away), "American Idol" contestants leave their lives behind. So do family members who travel to Los Angeles to support their loved one — on their own dime.

MORE FROM AMERICAN IDOL

Happy birthday, Simon, the best mean Brit ever

Happy birthday, Simon, the best mean Brit ever ‘Idol Gives Back’ returns to ‘American Idol’ Ellen brings EveryFan sensibility to ‘Idol’ Paula Abdul wishes Ellen luck on ‘Idol’   Add American Idol headlines to your news reader: