As "American Idol" celebrates its 500th episode & Season 13 comes to a close, here's our countdown of "American Idol" alums' biggest Hot 100 hits ever - and the untold stories behind the songs.

70

"Temporary Home" - Carrie Underwood

Hot 100 Peak: No. 41 (2010)

In his book, "The Purpose Driven Life," Pastor Rick Warren writes that this world is a "temporary home" and that when we leave here, it is not the end of existence. That was Underwood’s inspiration when she met with songwriters Luke Laird and Zac Maloy. "Carrie brought in the idea and had the title. I was just lucky to be in the room," says Laird. "She didn’t have the verses written, but knew what she wanted the verses to be about. I was strumming on the guitar. Carrie had the melody. It was a dream co-write. Carrie knew exactly where she wanted the story to go."

69

"What About Now" - Daughtry

Hot 100 Peak: No. 18 (2008)

"Clive Davis let me have my way on the first album," says Chris Daughtry. "He really let us take the reins." So when the legendary music executive asked the band to listen to a song written by former Evanescence members Ben Moody and David Hodges along with Josh Hartzler, the group was happy to consider "What About Now" for that debut album. It was the fifth and final single from Daughtry's first set to chart on the Hot 100 and the fourth extract to reach the top 20.

68

"Invisible" - Clay Aiken

Hot 100 Peak: No. 37 (2004)

Some people found the words to this song a bit creepy. "The lyrics are a little bit weird," Aiken concedes, agreeing with a Billboard reporter that he was singing about observing someone in their bedroom as a character invented by the songwriters, not himself. "I don't think people think that I'm actually watching somebody in their room. That's kind of nasty, and I don't encourage [it].

67

"See You Again" – Carrie Underwood

Hot 100 Peak: No. 34 (2013)

Underwood wrote three songs for the film "The Chronicles of Narnia: The Voyage of the Dawn Treader" with Hillary Lindsey and David Hodges. The song chosen for the soundtrack was "There’s a Place for Us," but "See You Again," a tale of seeing loved ones in the afterlife, did not go unreleased. Underwood recorded it for her "Blown Away" album and it was the fourth single issued from that set.

66

"Nothin' to Lose" - Josh Gracin

Hot 100 Peak: No. 39 (2005)

Marcel Chagnon was signed to Mercury when he wrote this song with Kevin Savigar. Featuring rapid-fire lyrics, it appeared on his first album, released under the singular name Marcel. "Unfortunately his record didn't perform in the way we'd hoped," says Savigar. Gracin's producer, Marty Williams, stopped by the offices of music publisher Almo-Irving to find songs for the season two finalist's debut set and passed on everything. He was about to leave when he asked, "What about that song Marcel did?" Savigar recalls, "My publisher slyly said, 'I was just about to play you that one.' They went in and cut the song and it went to No. 1. Later I saw Josh at a party in Nashville and I asked him, 'Did you cut that all in one piece?' He said, 'He made me do it over and over and over again!'"

65

"Over It" - Katharine McPhee

Hot 100 Peak: No. 29 (2007)

Billy Steinberg and Josh Alexander played "Over It" for Clive Davis in his bungalow at the Beverly Hills Hotel and Davis said he wanted the song for McPhee. Steinberg, who produced the song with Alexander, believes that "Over It" was not "in her comfort zone," adding, "We were hell-bent on getting the tonality right. We nearly pushed her over the edge to get it exactly the way we wanted it."

64

"September" - Daughtry

Hot 100 Peak: No. 36 (2010)

"On the last date of the Bon Jovi tour I picked up my guitar to rehearse for the night and came up with the riff for 'September,'" says Chris Daughtry. Bandmate Josh Steely sent Chris a voice memo with some lyrical ideas and Chris sent back a lyric based on Steely's outline. "He said it was exactly what he was going for, remembering the summer and going back to school. When I was a kid, summer was a big thing, not so much now. I kept bugging the label that 'September' had to be a single, and be released at the time of the year when it will have meaning." "September" debuted on the Hot 100 at the end of August 2010. On the Adult Contemporary chart it had a 52-week run, lasting through every season.

63

"Free Yourself" - Fantasia

Hot 100 Peak: No. 41 (2005)

Missy Elliott wanted to create something for Fantasia that every woman could relate to. Elliott was inspired by what she calls the "unorthodox" structure of El DeBarge’s songwriting, using a B-section rare in contemporary R&B. "I had Jazmine Sullivan do the demo track," says Elliott. "When Fantasia heard her version, she had to take it up a notch, vocally." The season three winner recorded "Free Yourself" in less than an hour. "With Fantasia, you feel like you get your money’s worth," Elliott professes about seeing the American Idol in concert. "She’s incredible. I would never want to go on after her."

62

"God Bless the U.S.A." - American Idol Finalists

Hot 100 Peak: No. 4 (2003)

Season two's top 10 finalists performed this Lee Greenwood song as a group effort, but not before rewriting the line, "and I won’t forget the men who died." Susan Slamer, music supervisor on the first four seasons of "Idol," explains: "Josh Gracin, who was a Marine, decided that since men and women have died, the lyric should be changed to reflect that." Slamer had to call the publisher to get permission to change the lyric to "the ones who died" – and was turned down. Slamer suggested the publisher sue the show, so "Idol" could go public with the refusal and see how it played out in the press for Greenwood. The words were altered per Gracin's request, both on air and on the single released to raise funds for the American Red Cross.

61

"Solitaire" - Clay Aiken

Hot 100 Peak: No. 4 (2004)

Celebrity judge Neil Sedaka was moved to tears by Aiken's season two performance of this song, written 31 years earlier with Phil Cody. "I was overwhelmed by Clay's voice and I said, 'I've lost the song. It will forever be a Clay Aiken song.' The next night I was having dinner at Spago and Clive Davis came over and told me, 'We're going to record "Solitaire" with Clay.' Then I heard the record didn't come off well and it was not included in Clay's 'Measure Of A Man' CD. Clive said, 'I feel terrible, Neil. I'm going to re-record it.' I never heard the original, but the second recording was brilliant. Brilliant!"

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