Chart Watch Extra: Idol vs. Idol

Who's the biggest recording star to come out of American Idol? I really think we should call it a tie. Carrie Underwood has sold more albums, but Kelly Clarkson has sold more individual songs. Just this week, Clarkson's #1 smash "Stronger (What Doesn't Kill You)" pulled ahead of Underwood's 2007 hit "Before He Cheats" to become the best-selling song by an Idol alumnus. "Stronger" has sold 3,510,000 copies, 1K more than Underwood's sassy revenge fantasy.

(Want to know what's in third place? It's "No Air," the melodramatic 2008 collabo by Jordin Sparks & Chris Brown, which has sold 3,437,000 copies, according to Nielsen SoundScan, which tracks sales for Billboard.)

Three other Clarkson songs have sold more than 2 million copies: Her sassy 2009 hit "My Life Would Suck Without You" (2,641,000); her turbo-charged 2005 smash "Since U Been Gone" (2,487,000) and "Don't You Wanna Stay," her award-winning 2011 collabo with country star Jason Aldean (2,105,000).

Underwood has only one other song that has topped the 2 million mark: her 2006 hit "Jesus, Take The Wheel" (2,030,000). The song was Underwood's first #1 on the Hot Country Songs chart and brought her the first of her five Grammys.

Clarkson has four songs whose current sales tallies are between 1.5 million and 2 million: her 2009 hit "Already Gone" (1,766,000); her 2004 hit "Breakaway" (1,733,000); her 2005 hit "Because Of You" (1,698,000) and her 2011 hit "Mr. Know-It-All" (1,593,000).

Underwood has three songs whose current sales tallies are in the 1.5-2 million range: Her 2009 hit "Cowboy Casanova" (1,864,000); "Remind Me," her 2011 collabo with her frequent CMA Awards co-host Brad Paisley (1,577,000) and her 2008 hit "All American Girl" (1,548,000).

Album sales are where Underwood leads the Idol pack. Underwood has sold 13,205,000 albums to date, compared to 11,664,000 for Clarkson. Underwood's best-selling album is her first, Some Hearts, which has sold 7,214,000 copies. Clarkson's biggest is her second, Breakaway, which has sold 6,237,000 copies.

Underwood's first three albums have all topped 2 million. Her fourth, Blown Away, has sold 622K copies in its first nine weeks.

Clarkson's first five albums have all topped 800K. Her current album, Stronger, has sold 846K copies in 36 weeks. Clarkson's lowest-selling album is her 2007 album My December, which has sold 832K copies to date. That album was the subject of a dispute with record company management (about artistic freedom) that became very public.

Clarkson moved in on Underwood's country turf when she recorded her duet with Aldean. "Don't You Wanna Stay" topped the country chart for three weeks, and even received a CMA Award for Musical Event of the Year.

Both women are big Grammy winners. Underwood has won five Grammys. Clarkson has won two. Underwood is the only Idol alum to win (or even receive a nomination for) Best New Artist. Clarkson is one of only two Idol alums to win a Grammy for having the year's best album in a given genre. Breakaway won as Best Pop Vocal Album of 2005, beating a high-powered field which also included Paul McCartney, Sheryl Crow, Gwen Stefani and Fiona Apple. (The other is JenniferHudson, whose eponymous debut album was voted Best R&B Album of 2008.)

Clarkson and Underwood are both so good, I think both would have made it with or without Idol. Idol is lucky to have found them. They give credibility to the show. The two women appear to be friendly rivals. I hope they're able to take in good humor the stories (such as this one) that continually compare them. The stories merely demonstrate that they are far and away the two biggest stars in Idol history.

It would be great if these two talented women someday collaborated in some way.

Incidentally, I said at the outset that Clarkson's "Stronger (What Doesn't Kill You)" is now the best-selling song by an Idol alum. I'm talking only about contestants. The best-selling song by anyone associated with the show is "On The Floor" by Jennifer Lopez featuring Pitbull, which has sold 3,588,000 copies. J.Lo's career was revived in 2011 by her stint a judge on Idol. (At the rate "Stronger" is going, it will pull ahead of "On The Floor" in about three weeks.)