Randy Jackson is making no apologies for the "American Idol" theme weeks, even if you would personally rather see a Lady Gaga-themed week over a Motown-themed week. According to the judge, if you really want to prove you've got the chops, you'd better be able to belt out some old -school tunes -- that's the mark of a true singer.

"Here's the problem with [contemporary theme weeks] -- guess what? It's a competition. I know that you know the latest Lady Gaga song," Jackson told MTV News. "I happen to think that songs of yesteryear are better songs and are harder to sing, so they create more difficulty for you who listens to the radio everyday."

Jackson explained that "Idol" competitors have to prove that they have the pipes to take on the big songs -- so if you want to sing a Ke$ha tune, "Idol" may not be the show for you. (Although Jackson hopes that Ke$ha takes no offense to that.) "Give me Sinatra. Give me somebody who's just really emoting and engaging and making you believe.

"Give me Motown," he continued about the advantages of singing older songs instead of newer hits by newer artists. "Give me the greatest rock band ever, in my estimation -- Led Zeppelin. The degree of difficulty to play Led Zeppelin music, let alone sing it, is so off the Richter scale. This is a competition. 'Idol' is like the Olympics for singers. We want to make it tougher for them."

Get your "Idol" fix on MTV News' [article id="1486475"]"American Idol" page[/article], where you'll find all the latest news, interviews and opinions.