If you were one of the millions watching the 2011 Billboard Music Awards, you witnessed a star-studded night full surprise performances  (Britney Spears!) emotional tributes ( Beyonce  and Neil Diamond ), A-list collaborations (Mary J. Blige with Lil Wayne) and much more. But there was plenty of buzzworthy action going on behind-the-scenes, too -- and not just during Sunday night's big show, but over two days of rehearsals at the MGM Grand Arena in Las Vegas. Here are the top 15 things that weren't shown on TV:
1. Of his six Billboard Music Awards wins (seven, counting Billboard.com's Fan Favorite Award), Justin Bieber was most proud of earning Top New Artist. The best moment, he said backstage after his wins, "was seeing my mom's eyes and how proud she is." Bieber said he is taking a month off and will then start working on his next album, which he hopes has songs with "meaning and significance. I want to focus on myself and get into what I'm feeling."
2. "Is that Robin Leach?," Snoop Dogg screeched, as a question was delivered to him from the "Lifestyles of the Rich and Famous" host turned newspaper columnist. Snoop immediately launched into a spot-on imitation of Leach's over-the-top introduction, rattling off his own accomplishments in a thick Australian accent that had the press room convulsing with laughter. Turning serious, Snoop gave props to Britney Spears. "She's back on her thing. She got it back right ... We should commend her."
3. U2 made a surprise visit backstage after winning the Top Touring Artist Award. "It's a magic trick," Bono said backstage, addressing how the band's team made the 360 tour feel intimate in stadiums. the Edge added "thinking about how many people came to the shows -- 7 million. I still can't get my head around that figure." U2 has resumed touring in the U.S. though Bono did suggest they continue to work on new material. "There are lots of U2 album," he said, "why would they want another one? We're in the laboratory experimenting."
4. Taylor Swift explained the approach to her upcoming tour. "Telling a story is one of my favorite things to do. (The show has) lots of moving parts. There are elements of surprise, pyro, very theatrical (parts) -- lots of fun stuff that I finally get to do...We took each song and went on a song-by-song basis to make each special." Swift, who added three Billboard Music Awards to her staggering number of awards won in her short career, said, "I love being at these all-genre awards shows. ... I still freak out when my name is called and I can't believe I got to win three Billboard awards. Fans have done it all for me, and I hope that during my tour I get to meet as many people as possible and say thank you."
5. Pitbull said his new album "Planet Pit," slated for a June 21 release, will be the "result of seeing cultures united through music. I try not to categorize what I do -- I say I perform music."
6. In the hour before the show started, Randy Jackson held court backstage, warmly greeting Taio Cruz, members of Far East Movement, Mercury Records president David Massey, background singers and even a few members of the production crew. Bear hugs all around.
7. With summer around the corner, it is already plenty hot in Las Vegas -- 89 degrees -- even at 5 p.m. PT when the show started. It was at least 15 to 20 degrees warmer outside than onstage, one reason why Rihanna, decked out in her all-white "S&M" performance attire, was driven a couple hundred feet from her trailer to the backstage entrance.
8. Performers are always asked in the press room who they would like to collaborate with. Among the answers: Justin Bieber picked Jay-Z and will.i.am; Taylor Swift said she would like to co-write with Bruno Mars; Snoop Dogg was adamant about Sade; and Pitbull concluded his list with the late Celia Cruz. Yes, he wants to incorporate one of her recordings into one of his songs.
9. The Boston band Gentlemen Hall won the Chevrolet Battle of the Bands, driving from New England to Las Vegas to perform on Wednesday in the contest. While driving across the country, they stopped along the way to perform impromptu shows, using the Chevy's speakers as a PA for guitar and synthesizer. The song they performed on the show, "All Our Love," will be part of a six-song EP being released this summer. On the thrill of going from a club band to making a national TV appearance in a week, Gentleman Hall's frontman said, "How do you manage one higher level of adrenaline after another?"
10. Before the show started, Eric Stonestreet, who plays Cameron on "Modern Family," was seen inquiring about Lady Antebellum's vintage organ and audio gear prior to taking the stage in a dueling Elvis routine.
11. Zach Filkins of OneRepublic came prepared to capture the event, snapping photographs of backstage activities before the band made its way to their dressing room.
12. The 100 youngsters who filled the mosh pit were lined up and ready to go at 2:30 p.m., two and a half hours before showtime. The most commonly discussed names among the kids? Nicki Minaj and Keith Urban.
13. Neil Diamond's rehearsal time was 9 a.m. Friday, and at 9:15 he was belting out "Sweet Caroline" and "America," singing as well as he did
on the broadcast.
14. Some seriously high heels were seen on the feet of singers and dancers all across the backstage area before the show started. Ke$ha, sporting sky-high stilettos, took extra caution. She had assistants holding each arm as she made her way gingerly to the stage.
15. Host Ken Jeong practiced his Bach and Coldplay every day for a month in preparation for his bit during the opening sequence of the telecast. "All comedians want to be rock stars, he said. "(Hosting the Billboard Music Awards) provides a lifetime of memories for me." During one break, Jeong tested his microphone midway through the performance by saying, "I'm Rick James, bitch." Now that's truly old school.