(CNN) -- It's an iconic scene from the the 1983 film "Risky Business."
A young Tom Cruise slides across his living room floor, clad only in a button-down shirt and some tighty whities, and lip-syncs Bob Seger's "Old Time Rock & Roll" into a candlestick holder.
The moment highlighted a common dream that has fed the popularity of singing competitions: a love of singing and a desire to take to the stage.
The concept behind these reality shows is simple: Take some unknowns, males and females, put them on stage in the national spotlight and watch them wow the world with their talent. Or they can fail miserably, which is sometimes even more fun to watch and satisfies a human urge to judge.
If the contestants are good enough, and sometimes even not, the rewards include fame and fortune -- well at least fame.
From "The Gong Show in the 1970s to "Star Search" in the 1980s, the giant that still is "American Idol," "America's Got Talent" and newcomers "The Voice," "CMT's Next Superstar" and "The X Factor," the love affair with singing competitions continues even as album sales decline.
"At the core, these shows give an opportunity for ordinary people to become stars," said M. Tye Comer, editor for Billboard.com. "Whether or not that person goes on to become the 'American Idol' or win 'The X Factor,' you are giving them a platform to sing in front of millions of people, which is something a lot of people aspire to even if they verbalize it or not."
Despite declining ratings over the years, "American Idol" reigns supreme as one of TV's most popular shows in its 10th season on the air. According to the website TV by the Numbers, for the week of April 4-10, "Idol" "was the highest-rated program of the night in all key demographics and outperformed the next highest-rated program of the night by +103% (in the coveted 18-49 demographic).
Waiting in the wings with hopes to emulate 'Idol's" success are NBC's "The Voice," which is set to premiere April 26, and "The X Factor," debuting in the fall.
Like "Idol," which brought on new judges Jennifer Lopez and Steven Tyler this season, "The Voice" will also feature a few notables -- in this case pop star Christina Aguilera, Maroon 5 frontman Adam Levine, singer Cee Lo Green and country star Blake Shelton, who will be mentors for the show's contestants.
"The X Factor" shares an even stronger link with "Idol"; the new show's creator, Simon Cowell, was an original judge on the latter.
But the program that can boast the biggest "Idol" pedigree is "CMT's Next Superstar," whose executive producer, Nigel Lythgoe, was co-creator of "Idol," itself a spinoff of the popular former British show "Pop Idol," which was created by Simon Fuller, the founder of 19 Entertainment.
Lythgoe and his son Simon (who also was a producer on "American Idol") are the driving forces behind the country music talent search, which the younger Lythgoe said is not at all like "Idol."
"It's not the shiny, glitzy show you are used to seeing on a singing competition," Simon Lythgoe said. "We get down and dirty on this show."
That includes changing locations each episode and different challenges for the contestants, Lythgoe said. He said he wanted it to be different from the start.
"I don't think there was a need for another show (like "Idol") with 'The X Factor' and 'The Voice' coming out," Lythgoe said. "We're after a different type of artist to be honest.
"This isn't 'American Idol,' where Simon Cowell knocks people down or you have bad singers. We turned the country upside down and found what we believe to be 10 of the best country singers around."
Finding those key differences can be important for a show's survival, said Lyndsey Parker, who writes the "Reality Rocks" column for Yahoo!
"I watch them all and give them a chance because I am a glutton for these types of shows, as I think a lot of America is," Parker said. "One thing I think is kind of a worry is that there are only so many hours in a day to watch TV and so much mental or emotional space to invest in contestants, vote for them and root for them. At some point, people are going to get burned out because ... they start to become interchangeable and dilute each other."
Parker said viewers enjoy watching a competition but also having a hand in changing the direction of contestants' lives.
"People love a Cinderella story and having a stake in that," she said. "The biggest example of that is Fantasia (Barrino, the 'American Idol' winner on season three) who was a struggling, illiterate, single mom, and we voted for her. Now she's a Grammy winner."
Richard Drew is a television producer who writes about reality shows for his blog "Remote Patrolled." In his native England, he worked on the singing competition show "Fame Academy," hosted by Cat Deeley, known to fans stateside for hosting "So You Think You Can Dance."
Drew said music competition shows are beloved around the world.
"When we watch TV and we get caught up in people's stories, watching them week after week and building a connection with them, I think that's exciting," he said. "That's why so many of these shows are so heavy on the back stories. We love seeing people develop week (after) week and get better and better."
He said he also believes social networking is playing a role in helping further these shows' popularity.
"With Twitter and Facebook we want to have our say," Drew said. "We don't want record companies telling us who will be the next star; we want a hand in deciding that."
On a Facebook page dedicated to "American Idol," Shelley Mattes posted, "Ok tomorrow all you fans vote for the only two girls there, Vote for Haley (Reinhart) and Lauren (Alaina) !!!! Get those guys out!!! I am protesting!!! For PIA!!!!!" in honor of perceived front-runner Pia Toscano, who was surprisingly eliminated from the Top 9.
Ellen Smith tweeted: "Dear Idol Fans- tonite after watching idol let's vote for the best performance please instead of trying to save some of the worse ok."
No show seems to be building as much anticipation as Fox's "The X Factor." The Cowell-headed series won't air for months, and already there has been an enormous amount of media attention paid to the judges (Antonio "L.A." Reid is the only name confirmed thus far) and whether "Idol" fans will follow Cowell to his new show.
Alan Frutkin, senior editor with Mediaweek, covered the first round of auditions for "The X Factor" in Los Angeles, which he said drew a crowd of 15,000 and said the interest is high.
"Most people relate to these shows because most everybody sings," Frutkin said. "Whether they sing poorly or well, in the shower or in their car, we can all imagine ourselves in these contestants' place, and there is an inspirational thrill. There's also that transformational aspect involved."
The British-born Simon Lythgoe of "CMT's Next Superstar" has a theory as to why the shows have found such a solid fan base in this nation.
"It's the rags-to-riches story, which is very much the American dream," he said. "And just that fact that you can vote is very democratic and American."