$TILL NO. 1: Ke$ha  says that the "$" in her name is an ironic ode to her belief that, "There is no correlation between happiness and amounts of money." 
Regardless, the cash is pouring in, thanks to the success of "TiK ToK," which leads the Billboard Hot 100 for a second frame.
Click here  for Billboard director of charts Silvio Pietroluongo's analysis of the singer's record-setting sales week.
HIGH FIVE: A fellow rookie diva, if somewhat less conventional, rewrites history atop the Billboard 200.
As previously reported,  with a fifth week in charge for "I Dreamed a Dream," Susan Boyle  is the first artist in the Billboard 200's 53-year chart history to enter the list at No. 1 with a debut album and spend five consecutive weeks at the summit. In second place with three weeks each at No. 1 out-of-the-gate are two other female artists: Lauryn Hill ("The Miseducation of Lauryn Hill," 1998) and Ashanti  ("Ashanti," 2002).
Another new artist bears mention for a lofty launch on the Billboard 200. Billy Ray Cyrus  spent a robust 17 of his first 18 weeks at No. 1, but, because the lone week not tallied at the summit was his first, the record for most frames at No. 1 from the start belongs to Boyle. Cyrus' "Some Gave All" entered the chart at No. 4 on the survey dated June 6, 1992. The following week, the set began an uninterrupted 17-week residency at No. 1 through Oct. 3, 1992.
MANY 'MOON'S: Four weeks ago, Pink Floyd 's "Dark Side of the Moon" returned to the Billboard 200 following a gap of more than 21 years, extending its record to a 742 total weeks on the chart.
This week, the collection re-enters at No. 91, upping its total to 743 frames on the survey. It's not, however, the only version of the album on the chart.
At No. 157, the Flaming Lips/Stardeath and White Dwarfs with Henry Rollins and Peaches arrive with a song-by-song cover of "Dark Side of the Moon."
The set is the second revered rock album to return in tribute form in recent weeks. In September, Cheap Trick  spent a week at No. 83 with "Sgt. Pepper Live," an update of the Beatles ' seminal "Sgt. Pepper's Lonely Hearts Club Band."
ON THE CHART AGAIN: The iconic Willie Nelson  extends his career chart span on Country Songs to 47 years, nine months and three weeks, as "Baby, It's Cold Outside," featuring Norah Jones  (No. 55), becomes his 122nd entry.
Billboard senior chart manager Wade Jessen notes that Nelson's first chart appearance likewise sported a guest artist credit. "Willingly," with Shirley Collie, debuted the week of March 17, 1962 eventually peaking at No. 10. (Non-chart statistics: Collie divorced her husband, renowned country DJ Biff Collie, to marry Nelson in 1963. The union lasted until 1971, marking the second of four marriages for Nelson).
Here is a look at the acts to boast 100 or more entries since the list launched this chart week in 1944, the same year that "Baby, It's Cold Outside" was written by Frank Loesser:
165, George Jones
143, Eddy Arnold
135, Johnny Cash
122, Willie Nelson
106, Dolly Parton
106, Ray Price
104, Hank Williams Jr.
100, Merle Haggard
"Baby, It's Cold Outside" makes its third visit to Country Songs. In 1949, comedic duo Homer and Jethro, with June Carter, took the song to No. 9. In 2006, a studio-created duet by Dean Martin and Martina McBride  rose to No. 44.
THERE GOES SANTA CLAUS: After this week, the Holiday Songs airplay chart goes into hibernation until November. Which carols led the list the most this season?
Burl Ives ' "A Holly Jolly Christmas" reigned for four weeks, Brenda Lee 's "Rockin' Around the Christmas Tree" ruled for two frames and Mariah Carey 's "All I Want for Christmas Is You" decorated the penthouse for one week.
Just three songs released in the 2000s appeared on the chart this yuletide season: Josh Groban 's "O Holy Night," Faith Hill 's "Where Are You Christmas?" and NewSong 's "The Christmas Shoes."
THAT'S A RAP: While the ever-inventive DJ Earworm has melded the top 25 Hot 100 hits of 2009 into the mashup "United State of Pop 2009,"  Skillz makes his annual return to R&B/Hip-Hop Songs with his take on pop culture over the past 12 months.
Skillz bows at No. 100 on the survey with "2009 Rap Up." The Virginia wordsmith sent previous commentaries onto the chart in 2006 (No. 67), 2007 (No. 77) and last year (No. 55).
CHART BEAT BITS: Beginning on the Billboard 200 at No. 2, Mary J. Blige 's "Stronger withEach Tear" fares even better on R&B/Hip-Hop Albums, where the set storms 92-1 following a bow last week due to street date violations. Now with nine No. 1s on the latter chart, Blige trails only Aretha Franklin  (10 No. 1s) for most leaders among women in the tally's 45-year history ...
On R&B/Hip-Hop Songs, Melanie Fiona  ascends to her first No. 1 with "It Kills Me." Fiona is the second Toronto-born act to preside over the chart in the past year: Drake  dominated with "Best I Ever Had" last summer (and dips to No. 2 this week as a guest on Trey Songz ' "I Invented Sex"). Billboard senior chart manager Raphael George notes that Toronto sports a vibrant R&B and reggae culture, and that the city has also produced hip-hop newcomer Kardinal Offishall  ("Dangerous") ...
Muse 's "Uprising" becomes one of just seven tracks to lead Alternative Songs for at least 15 weeks. Over the chart's 21-year archives, Foo Fighters ' "The Pretender" holds the longevity mark with 18 weeks at No. 1 in 2007 ...
Lifehouse  ascends to its sixth Adult Pop Songs top 10, as "Halfway Gone" rises 11-10. Especially notable are two of the song's writers: Jude Cole  and Kevin Rudolf . While the latter is best-known for 2008's "Let It Rock," Cole's chart history as an artist dates the early '90s, when he placed five songs on the Hot 100, led by the No. 16-peaking "Baby, It's Tonight." Now Lifehouse's manager, Cole has co-written four of the band's Adult Pop Songs top 10s ...
The reign in Spain ... is followed by a similar success story in the U.S. for Inna. After topping the Spain singles chart and going top 10 in Belgium, Hungary and the Netherlands, the 23-year-old Romanian enjoys her first No. 1 on a U.S. survey. Inna's track "Hot" climbs to the top of Hot Dance Airplay (viewable at billboard.biz ).
ALL IS QUIET ON NEW YEAR'S DAY: This marks the last edition of Chart Beat for 2009. We'll return with a new posting, Chart Highlights, Monday (Jan. 4), followed by daily entries and the return of our - and your - Ask Billboard Q&A mailbag each Friday.
To chart fans everywhere, a sincere appreciation for visiting billboard.com and reading Chart Beat, as well as for sending insightful e-mails throughout 2009. It's a joy to write the column, and all the more fun with the input of fellow, passionate chart-watchers.
Happy new year, and here's to a perfect '10!
- Chart Beat