BEYONCE & LADY GAGA: After "Telephone," by Lady Gaga  featuring Beyonce , topped Dance/Club Play Songs in February, "Video Phone" returns the superstar duo to the chart's top spot. The list's new leader credits the pair in reverse order: Beyonce featuring Lady Gaga.
"Video Phone" marks Beyonce's 14th No. 1 on Dance/Club Play Songs and Lady Gaga's sixth topper. With the coronation, Beyonce passes Whitney Houston , who's collected 13 No. 1s between 1987 ("I Wanna Dance With Somebody (Who Loves Me)" and last November ("Million Dollar Bill").
Here is a look at the artists with the most No. 1s since Billboard's Dance/Club Play Songs chart launched in 1974:
40, Madonna 
19, Janet Jackson
15, Mariah Carey
15, Kristine W
13, Whitney Houston
Beyonce first commanded Dance/Club Play Songs with "Crazy in Love" in 2003. "Video Phone" is her sixth consecutive No. 1 on the chart, a streak that began with "Diva" in March 2009 and has continued with "Halo" and "Sweet Dreams" last year and "Why Don't You Love Me," "Telephone" and "Video Phone" this year.
"Telephone" concurrently marks Lady Gaga's second debut in the last three weeks on Adult Contemporary, where it starts at No. 28. In its third chart frame, "Bad Romance" rises 26-24. The tracks join the singer's "Paparazzi," which ranks at No. 18 in its 17th week on the list. The lattermost song stands as Lady Gaga's highest-charting single on Adult Contemporary, having reached No. 15 earlier this month.
RIHANNA & KE$HA: Rihanna  notches her fifth No. 1 on the Pop Songs tally, as "Rude Boy" rises 2-1. With the ascent, Rihanna ties Avril Lavigne , Pink , Britney Spears  and Justin Timberlake  for second-most leaders in the chart's 17-year history. In the lead are Beyonce, Mariah Carey  and Lady Gaga, each with six No. 1s.
Up 13-9 on Pop Songs, Ke$ha 's "Your Love Is My Drug" becomes just the second song in the last year-and-a-half to reach top 10 in a mere four weeks, joining Young Money's "BedRock" in February. In February 2009, Kelly Clarkson  completed a four-week climb to the top 10 with "My Life Would Suck Without You."
SHAKIRA (& GLORIA & PAULINA): With a 2-1 lift for "Gitana," Shakira  earns her 12th chart-topper on Latin Pop Songs. She breaks a tie with Cristian Castro and now claims second place to herself for most No. 1s in the chart's archives after Enrique Iglesias ' 14 No. 1s.
The advance of "Gitana" grants Shakira her first set of three consecutive leaders on Latin Pop Songs. "Loba" reigned for 11 weeks beginning in August, and "Lo Hecho Esta Hecho" ruled in January.
"Gitana" spends a second week atop the newly-unveiled Latin Pop Digital Songs chart, which along with 20 additional genre-specific download surveys, are viewable at billboard.biz .
COMPLETE BEAT: Last night's preview for next week's episode of "Glee" teased the creation of the "Glist," a school-circulated "Glee-list" ranking the troupe's most desirable members, but this week's Billboard 200 could be similarly renamed, as "Glee: the Music, the Power of Madonna" enters at No. 1 . Check tomorrow's posting of Chart Beat for more on the series' historic week on the Billboard 200 and Billboard Hot 100. As they are each Thursday, all charts will be refreshed tomorrow on billboard.com at 11 a.m. ET.
- Chart Beat