Three Whitney Houston albums crowd the top 10 on The Billboard 200. Houston is one of just six artists to have three or more of the 10 best-selling albums in the U.S. since August 1963, when Billboard merged separate mono and stereo charts into one comprehensive listing. (Coincidentally, that was also the month that Houston was born.) The five other artists to achieve this feat are Peter, Paul & Mary, The Beatles, Herb Alpert & the Tijuana Brass, Simon & Garfunkel and Michael Jackson.

This makes Houston the first woman to achieve the feat, and the second (solo) star to achieve it posthumously. As happened after Jackson's death three years ago, fans are looking for a keepsake of a star they loved (or once loved). A CD is ideal for this purpose.

Between them, Whitney Houston and Adele have half of the albums in the top 10 on the Billboard 200. Houston has three. The Greatest Hits holds at #2, The Bodyguard soundtrack vaults from #38 to #6 and Whitney Houston leaps from #37 to #9. This is the best showing by any artist since the Beatles had five of the 10 best-selling albums in the U.S. in September 2009, after their catalog was digitally remastered. Two months before that, Michael Jackson had six of the 10 best-selling albums in the U.S. (for two weeks running) in the wake of his death.

Adele has two albums in the top 10. 21 holds at #1 for the 22nd week. 19 drops from #4 to #7. For 21, this is the longest run at #1 by any album since Prince & the Revolution's Purple Rain soundtrack logged 24 weeks on top in 1984-1985. 21 is #1 for the ninth week in a row. It's the first album to log nine consecutive weeks at #1 since the Titanic soundtrack was on top for 16 straight weeks in 1998.

[Photo: Mike Marsland/Wireimage]Adele's 21 this week breaks the record for the longest run at #1 by a female artist since The Billboard 200 album chart became a weekly feature in 1956. 21 logs its 21st week on top with a Grammy-fueled sales tally of 730,000 copies. The old record was held by Whitney Houston, whose The Bodyguard soundtrack held the top spot for 20 weeks in 1992-1993.

Adele is starting to close in on another record that Houston has held since 1986: the longest run at #1 on Billboard's Top Music Videos chart by a female artist. Adele's Live At The Royal Albert Hall is about to log its 12th week at #1. Houston's The #1 Video Hits held the top spot for 22 weeks in 1986. (More about that later.)

[Photo: John Shearer/WireImage]The sophomore slump is real. Just ask such short-lived phenomena as Vanilla Ice and Men at Work. But it certainly hasn't affected Adele, whose sophomore album 21 logs its 21th week at #1 on The Billboard 200. That puts the album in a tie with M.C. Hammer's 1990 album Please Hammer Don't Hurt 'Em for the longest run at #1 by any artist's sophomore album.

Sixteen sophomore releases have logged seven or more weeks at #1 since The Billboard 200 became a weekly feature in 1956. It's easy to see why so many sophomore albums have done so well. Having an album under their belts, the artists are warmed up. Their creative juices are flowing. They know what they're doing in the studio, but still have a lot to prove.