Don't you hate it when at the end of these audition shows you see mere glimpses of people who made it through to Hollywood? And why does it seem that the same tired old songs are sung over and over again in the auditions we do see?

The key to answering these questions is to learn about song rights.

If a performance is to be shown on TV — whether early in auditions or in the finals — the show must pay for or otherwise obtain the rights to do so from whoever owns the song. Sometimes this is referred to as getting clearance. If the producers don't want to pay, or if the owner of the song simply doesn't want to allow it, you won't see the performance — and this happens a lot before the Top 36 (Top 24 in previous years) are selected. By the time of the Top 36, the contestants must select from an approved list of songs that the show has already gotten clearance for, or try to obtain rights at the last minute.

This explains why someone like Jason Castro from last season, who made it to the Top 4, was never shown before the Top 24. "Idol" was never able to get clearance for one of the songs he performed during auditions, "Crazy" by Gnarls Barkley. As this story reports, it was because one of the song's two writers refused to sell the rights. Various reporters who have attended early auditions recount tales of dazzling auditions that never made it on the show presumably because rights couldn't be obtained. This is likely the case for some of those featured in rapid-fire montages of people gleefully running down the street, golden tickets in hand.

This is just conjecture on my part, but getting the sign-offs and/or forking out the cash for more current songs is probably tougher than doing so for an old Elvis song, for example. This might explain why you frequently see contestants doing old standbys in these early auditions.

There was an interesting incident concerning song rights late in Season 7. When David Archuleta sang Ben E. King's "Stand By Me," he infused it with a few lines from Sean Kingston's 2007 hit "Beautiful Girls." That reportedly angered "Idol" producers because the rights to "Girls" had not been secured. Archuleta and his father, Jeff Archuleta, later said they were under the impression they had gotten clearance.

Season 6 finalist Sanjaya Malakar of Federal Way reportedly talks about the frustrations of obtaining song clearance in his new book.