Adele's 21 tops the 9 million mark in U.S. sales this week. It's the first album to hit the 9 million plateau since Usher's Confessions hit the mark the week ending July 24, 2005. Remarkably, 21 reached the 9 million plateau faster than Confessions did, even though overall sales were much more brisk in 2004-2005. 21 has been out for 64 weeks. Confessions took 70 weeks to reach the magic number.

21 is the 29th album to sell 9 million copies since 1991, when Nielsen SoundScan began tracking sales for Billboard. It's the 24th regular studio album to reach this level. Studio follow-ups to the first 23 have achieved varying degrees of success.

It's too early to know if Jermaine Paul, the newly-crowned winner of Season 2 of The Voice, is going to become a recording star, but the show has done wonders for the careers of all four of its judges, especially Adam Levine. "Payphone" by Maroon 5 featuring Wiz Khalifa holds at #3 for the third week in its third week on the Hot 100. Even "Moves Like Jagger," Maroon 5's 2011 smash with Christina Aguilera, didn't hold up this well in its early outings. The song debuted at #8, but then dropped to #23 in its second week and #62 in its third. (That was its low point; it reached #1 in its 10thweek and stayed there for four weeks.)

"Payphone" tops the 1 million mark in sales this week. It's Maroon 5's fastest climb to "gold" status. 2007's "Makes Me Wonder" took seven weeks to sell 1 million copies. "Jagger" took nine.

Carrie Underwood this week becomes the first American Idol alumnus to land three #1 albums on The Billboard 200. Kelly Clarkson and Chris Daughtry's band Daughtry have each had two. Underwood scores with her fourth album, Blown Away, which follows 2007's Carnival Ride and 2009's Play On.

Clarkson was the first Idol alum to land a #1 album and also the first to land two. But she missed out on the chance to become the first to log three when her current album, Stronger, debuted and peaked at #2 in October. (Chris Daughtry likewise missed out on the chance to become first Idol alum to land three #1 albums when his band's Break The Spell debuted and peaked at #8 in November.)

"Somebody That I Used To Know" by Gotye featuring Kimbra this week becomes the first song in digital history to top 400K in weekly sales three times. The song sold 414K copies this week, down from 463K last week and 542K two weeks ago. It surpasses three songs that sold 400K copies twice: Flo Rida's "Right Round," Bruno Mars' "Grenade" and Lady Gaga's "Born This Way."

"Somebody…," which tops the Hot 100 for the third straight week, is the least overtly commercial of these four hits. It's a quirky alternative song, while the other three are mainstream hip-hop or pop. Also, Flo Rida, Mars and Gaga had all topped the Hot 100 with previous hits. By contrast, this is the breakthrough hit for both Gotye, a 31-year old musician who was born in Belgium, and Kimbra, a 22 year old singer from New Zealand.

Jack White's first solo album, Blunderbuss, debuts at #1 this week in both the U.S. and the U.K.  This marks the fourth time that the first solo album by a prominent member of a group or duo has reached #1 in both countries. Blunderbuss follows George Harrison's All Things Must Pass, George Michael's Faith and Beyonce's Dangerously In Love. All three of those artists had had "transatlantic #1" albums with their famous groups (the Beatles, Wham! and Destiny's Child, respectively) prior to their solo debuts. White nearly did too, but the White Stripes' 2007 album Icky Thump, which hit #1 in the U.K., peaked at #2 in the U.S.

Blunderbuss is White's eighth top 10 album on The Billboard 200, following three albums with the White Stripes, two with the Raconteurs and two with the Dead Weather. The White Stripes first cracked the chart in March 2002 with White Blood Cells. The Stripes' last three albums won Grammys as Best Alternative Music Album (which puts the band in a tie with Radiohead for the most wins in the category's 22-year history). White has amassed nine Grammy Awards in all.

Billboard's Gary Trust may have put it best: "How ironic that a song about something as old-fashioned as a pay phone sets a digital download record." "Payphone" by Maroon 5 featuring Wiz Khalifa sold 493K copies this week, which is more than any other song by a group or duo has sold in any one week in digital history. The old mark was set by the Black Eyed Peas' "Boom Boom Pow," which sold 465K copies in its first week in April 2009.

Only two other songs in digital history have sold as many copies in their debut weeks. Flo Rida's "Right Round" sold 636K copies in its first week in February 2009. Justin Bieber's "Boyfriend" sold 521K in its first week just three weeks ago.

Lionel Richie's Tuskegee tops The Billboard 200 for the second week. It's the first album that was released in 2012 to manage a second week on top. Albums by two legends (Bruce Springsteen and Madonna) were unable to pull this off, as were the sophomore album by the red-hot Nicki Minaj, the debut album by teen dreams One Direction and the soundtrack to the year's top-grossing movie, The Hunger Games.

Adele's 21 has held the top spot for nine weeks so far this year, but it was released in February 2011.

Florence + the Machine's MTV Unplugged enters the current Billboard 200 at #51. It's the highest-charting Unplugged album in a little more than five years, since Korn's MTV Unplugged hit #9 in March 2007.

Thirty-two artists have charted with Unplugged albums in the past 21 years. They're a surprisingly diverse bunch. In addition to the pop and rock artists who are most often associated with the series, Latin, R&B, hip-hop, traditional pop and Contemporary Christian artists are also represented. (Two Various Artists albums have also charted.)