Through the end of the year, Chart Beat is looking back at the biggest achievements on Billboard's charts in 2009 and throughout the past decade.

Tuesday, Dec. 15: Best of 2009, Part 1
Wednesday, Dec. 16: Best of 2009, Part 2

Tuesday, Dec. 22: Best of the 2000s, Part 1
Wednesday, Dec. 23: Best of the 2000s, Part 2

Tuesday, Dec. 29: 2009 By-the-numbers
Wednesday, Dec. 30: 2000s By-the-numbers

BEST OF 2009, PART 2

July

Just as he did in his life, Michael Jackson continues to break Billboard chart records (July 11). Following his passing June 25, Jackson commands the top nine positions on Top Pop Catalog Albums. His solo sets rank at Nos. 1-4 and 6-9, and a Jackson 5 compilation bows at No. 5. Jackson is the first artist to lock down the top four positions on the survey. He also places a record 21 entries on the 75-position Digital Songs chart (plus an additional four with his siblings) ...

(For further Jackson chart achievements, view a special edition of Chart Beat devoted entirely to the feats that helped the King of Pop don his crown.)

The Black Eyed Peas replace themselves at No. 1 on the Hot 100 (July 11), as "I Gotta Feeling," their second leader, swaps places with runner-up "Boom Boom Pow" after the latter track reigned for 12 weeks. The Peas have their own direct connection to Michael Jackson: on last year's 25th anniversary re-release of "Thriller," Fergie sang on "Beat It 2008," and will.i.am guested on "The Girl Is Mine 2008" ...

Miley Cyrus notches her first No. 1 on Adult Contemporary with "The Climb" (July 18). At 16 years and seven months, Cyrus is the youngest artist to top the chart since LeAnn Rimes entered the penthouse with "How Do I Live" in September 1997 just two weeks after her 15th birthday ...

Mariah Carey nets her 40th Hot 100 chart entry with the No. 11 bow of "Obsessed" (July 25). The song is also Carey's 33rd top 40 hit, tying her with Connie Francis. Among women, the pair trails only Madonna (48) and Aretha Franklin (43) for most top 40 titles ...

The star-studded July 7 memorial for Michael Jackson at Los Angeles' Staples Center spurs a debut on Digital Songs for USA for Africa's "We Are the World," co-written by Jackson and Lionel Richie (July 25). The song appears on a Billboard chart for the first time since 1985, when it topped the Hot 100, R&B/Hip-Hop Songs and Adult Contemporary ...

August

Daughtry makes it two-for-two atop the Billboard 200, as its sophomore set, "Leave This Town," arrives at No. 1 (Aug. 1). Having reigned with its self-titled debut album, Daughtry is just the third group in the 2000s to begin with two No. 1s, following D12 and Danity Kane ...

As the Boy Who Lived has improved his wizarding skills over the years, so has he become more adept at conquering the Billboard 200 (Aug. 1). The soundtrack to "Harry Potter and the Half-Blood Prince" becomes the franchise's highest-peaking edition, apparating at No. 29 ...

Pearl Jam's "The Fixer" launches on Rock Songs at No. 2 after its first week at radio (Aug. 8). On Alternative Songs, the song starts at No. 11 to become the band's 34th entry dating to the arrival of "Alive" on the chart dated Jan. 25, 1992. In the Alternative chart's 21-year history, only U2 (37) has made more visits ...

"Loba," the Spanish-language version of "She Wolf," becomes Shakira's eighth No. 1 on Latin Songs (Aug. 29). She first led with "Ciega, Sordomuda" in 1998. Her 2005 hit "La Tortura," featuring Alejandro Sanz, holds the Latin Songs record for most weeks at No. 1 (25) ...

The Black Eyed Peas spend an unprecedented 20th straight week atop the Hot 100 (Aug. 29), as "I Gotta Feeling" logs an eighth frame at No. 1; "Boom Boom Pow" led for 12 weeks. The group passes the 19 consecutive weeks that Usher spent in charge with "Yeah!" and "Burn" in 2004. Adding to the Hot 100's momentous nature this week is the 70th chart week notched by Jason Mraz's "I'm Yours," which passes the 69-week stay of LeAnn Rimes' "How Do I Live" in 1997-98.

September

Carrie Underwood collects the highest debut by a female artist this year on Country Songs, as "Cowboy Casanova" ropes a No. 26 start (Sept. 19). Among all acts, Underwood's new hit ties Brad Paisley's "Then" for the year's second-best bow; Kenny Chesney's "Out Last Night" began at No. 25 in April ...

How long had it been since Whitney Houston presided over the Billboard 200? Until this week (Sept. 19), the superstar had last led when her soundtrack to the "The Bodyguard" spent its 20th and final week at No. 1 on the May 29, 1993, chart. This week, Houston returns to the throne with "I Look to You," her fourth No. 1 album ...

On Alternative Songs, "Notion" is Kings of Leon's third No. 1, all from their fourth set, "Only By the Night" (Sept. 19). "Sex On Fire" reigned for eight weeks, and "Use Somebody" ruled for three. On Adult Pop Songs, "Use Somebody" becomes the act's first No. 1 ...

Madonna rules Dance/Club Play Songs for a record-extending 40th time, rising 2-1 with "Celebration" (Sept. 26). She joins only two other artists in the history of Billboard charts to collect 40 No. 1s on a survey: George Strait (44) and Conway Twitty (40) have each attained comparable dominance on Country Songs ...

Jay-Z notches his 11th Billboard 200-topping album with "The Blueprint 3" (Sept. 26) and passes Elvis Presley as the solo act with the most No. 1s in the chart's 53-year history. Jay-Z now stands in second place among all artists, trailing only the group that debuts with two boxed sets: the Beatles, who've visited the summit 19 times. The Fab Four open at No. 15 with "In Stereo" and No. 40 with "In Mono."

October

Jimmy Wayne enters Country Songs with "Sara Smile," featuring the classic song's original performers, Daryl Hall & John Oates (Oct. 3). Wayne recalls, "13 years ago, I picked a Hall & Oates greatest hits CD out of a bargain box in the old Gaston Mall in Gastonia, North Carolina. I heard 'Sara Smile' for the first time, and I just felt as if the song was written for me" ...

After becoming the first country artist to win a Moonman at the MTV Video Music Awards Sept. 13, Taylor Swift continues breaking through barriers (Oct. 3). Her "You Belong With Me" becomes the first country crossover to top Radio Songs/Hot 100 Airplay since the list began incorporating Nielsen BDS-monitored data in 1990 ...

With a start at the Billboard 200 summit for "Love Is the Answer," Barbra Streisand is the only act to collect No. 1s in each of the past five decades (Oct. 17). The beloved entertainer extends the chart record for longest span of No. 1s among women: 44 years, 11 months and two weeks, dating to the coronation of "People" in October 1964 ...

Britney Spears' "3" rockets onto the Hot 100 at No. 1, marking just the 16th start in the top spot in the chart's history (Oct. 24). "3" becomes the shortest title to reach the Hot 100's pinnacle, passing the mark of three characters held by five previous No. 1 titles ...

For the second time since his passing, Michael Jackson has taken radio by storm. The King of Pop's "This Is It" earns its first Billboard chart ink with a No. 43 debut on R&B/Hip-Hop Songs (Oct. 24). The song is Jackson's landmark 50th career entry on the survey. Says Skip Dillard, operations manager of Inner City adult R&B WBLS (107.5 FM)/New York, "It seems that everyone remains attached to all things Michael. Reaction has been all-thumbs-up."

November

Zac Brown Band's "Toes" steps 2-1 on Country Songs, marking the act's second No. 1 in three tries (Nov. 7). Its debut chart entry "Chicken Fried" sizzled for two weeks at No. 1. The act is the first group to ascend to the summit with two of its first three chart entries since Dixie Chicks in 1998 ...

Jason DeRulo's "Whatcha Say" lifts 2-1 on the Hot 100 (Nov. 14). The singer is the fourth act this year to carry a debut chart entry to No. 1, following Lady Gaga ("Just Dance"), Jay Sean ("Down") and Owl City ("Fireflies"). Three rookies reigned last year ...

Lady Gaga becomes the first artist in the 17-year history of the Pop Songs chart to pull four No. 1s from a debut album, as "Paparazzi" rises 3-1 (Nov. 14). Billboard's 2009 Rising Star previously led with "Just Dance," "Poker Face" and "LoveGame" from her debut release, "The Fame." KAMP (97.1 Amp Radio)/Los Angeles assistant program director John Michael says, "What makes Lady Gaga different than every other artist is that she, quite frankly, sounds different than every other artist. In a world driven by people who tend to gravitate towards what is proven and comfortable, she has released a record full of hits that doesn't sound like anything else out there right now" ...

Since Billboard published its first all-encompassing R&B songs chart in the issue dated Oct. 20, 1958, only five titles have spent at least 14 weeks at No. 1 on what is now entitled R&B/Hip-Hop Songs. This week (Nov. 14), Maxwell's "Pretty Wings" becomes the latest member of the exclusive club. The fourth also joined this year, Jamie Foxx's "Blame It," featuring T-Pain ...

Taylor Swift's "Fifteen" pushes 46-38 to become the 13th top 40 hit on the Hot 100 from "Fearless," extending the record for most such entries from one album (including its "Platinum Edition" re-release). Tied for second with seven top 40 titles each are three sets by Michael Jackson ("Thriller," "Bad" and "Dangerous") and albums by Janet Jackson ("Rhythm Nation 1814") and Bruce Springsteen ("Born in the U.S.A.)"

December

Kelly Clarkson collects her second No. 1 on Adult Pop Songs, as "Already Gone" pushes 2-1 (Dec. 5). Clarkson ruled for five weeks with "Behind These Hazel Eyes" in 2005. "Already Gone" is the third No. 1 on the chart for the song's co-writer, Ryan Tedder, who co-authored Timbaland's "Apologize," featuring his band OneRepublic, and Leona Lewis' "Bleeding Love" ...

John Mayer returns to the summit of the Billboard 200 after six years, as "Battle Studies" launches at No. 1 (Dec. 5). His "Heavier Things" opened atop the chart dated Sept. 27, 2003 ...

With the revamping of the Billboard 200 to again include both current and catalog titles, one of the chart's landmark records is updated this week (Dec. 12). Pink Floyd's "Dark Side of the Moon" re-enters the chart for the first time since Oct. 8, 1988, logging a record-extending 742nd week on the survey. The collection debuted on the tally on March 17, 1973, and spent a week at No. 1 that April ...

Susan Boyle is the first solo female to enter the Billboard 200 at No. 1 with her first charted title since fellow U.K. native Leona Lewis last year (Dec. 12). The only other women to manage the feat this decade are Miley Cyrus, Ashlee Simpson, Beyonce, Kelly Clarkson, Ashanti and Alicia Keys ...

Holiday cheer to tide over Gleeks until the Fox series returns in April: the "Glee" cast is responsible for Wham!'s 1984 seasonal favorite "Last Christmas" making its first Hot 100 appearance (Dec. 19). The new version decks the chart at No. 63.