MTV EMAs Host Katy Perry Brings 'Cabaret' To Berlin
Mike Ruiz

WHAT HAPPENS TO 'VEGAS': On the Pop Songs/Mainstream Top 40 radio chart, Katy Perry becomes the fourth female artist since 2000 - and second this year following Lady Gaga - to earn at least two No. 1s from a debut album, as "Waking Up in Vegas" rolls 2-1. The song displaces "LoveGame" (1-2), Lady Gaga's third leader from her debut album, "The Fame."

"I Kissed a Girl," Perry's first chart entry from "One of the Boys," peaked at No. 2 on the list last summer. Follow-up "Hot N Cold" became her first No. 1, reigning for three weeks in the winter. Ballad "Thinking of You" reached No. 17 in March.

Here are the four female artists this decade to notch more than one No. 1 from their debut sets on Pop Songs:

Christina Aguilera, debut album "Christina Aguilera"
"Genie in a Bottle" (four weeks at No. 1)
"What a Girl Wants" (two weeks at No. 1)

Avril Lavigne, debut album "Let Go"
"Complicated" (eight weeks at No. 1)
"Sk8er Boi" (one week at No. 1)
"I'm With You" (four weeks at No. 1)

Lady Gaga, debut album "The Fame"
"Just Dance" (two weeks at No. 1)
"Poker Face" (five weeks at No. 1)
"LoveGame" (two weeks at No. 1)

Katy Perry, debut album "One of the Boys"
"Hot N Cold" (three weeks at No. 1)
"Waking Up in Vegas" (one week at No. 1)

"Waking Up in Vegas" also marks the first of the 196 songs that have reached the Pop Songs summit since the chart's 1992 launch to reference a city in its title. The only other No. 1 to include a geographical location in its name was Gym Class Heroes' 2007 leader "Cupid's Chokehold/Breakfast in America."

ROB RULES: Already the only male artist with multiple No. 1s on the Adult Top 40 airplay chart, viewable at billboard.biz, Rob Thomas collects his third leader, as "Her Diamonds" shines 3-1. He previously held sway as a guest on Santana's "Smooth," which spent a format-record 25 weeks on top in 1999-2000 and with "Lonely No More," No. 1 for 10 weeks in 2005.

With the coronation, Thomas ties Pink for most No. 1s by a solo artist. Here the acts with three or more No. 1s in the chart's 13-year history. Thomas appears on the list additionally as frontman of Matchbox Twenty:

5, Nickelback
4, Matchbox Twenty
3, Daughtry
3, Goo Goo Dolls
3, Pink
3, Santana
3, Rob Thomas

'CRAZY' LOVE: On the Triple A radio chart (also exclusive to billboard.biz), U2 collects its record-extending 20th top 10, as "I'll Go Crazy If I Don't Go Crazy Tonight" advances 13-10. The song is the third top 10 from "No Line on the Horizon," following "Get On Your Boots" (four weeks at No. 1) and "Magnificent" (11 weeks at No. 2).

Here is a rundown of the acts with 10 or more top 10s since the Triple A tally originated in January 1996:

20, U2
17, Dave Matthews Band
14, Coldplay
13, Sheryl Crow
13, Counting Crows
12, Jack Johnson
12, R.E.M.
11, Eric Clapton
11, The Wallflowers

Half of U2's 20 top 10s have gone all the way to No. 1, also a format record.

COMPLETE BEAT: Check back tomorrow when we run down feats from among all our charts, including the Billboard Hot 100, where the Black Eyed Peas close in on Usher's record for most consecutive weeks (19) spent at No. 1, thanks to the reigns of "Boom Boom Pow" and "I Gotta Feeling."

On Adult R&B, two legends return after lengthy absences. Whitney Houston previews "I Look to You," her first non-holiday album in seven years, with the title track at No. 23. At No. 38, Smokey Robinson extends his Billboard chart history to just shy of 50 years, bowing with a cover of Norah Jones' "Don't Know Why." The song is his first entry on the chart in four years.