Backstage, young performers mixed with legends, paying tribute and trading knowledge. Onstage, it was no different: From LMFAO's fever-pitched opening hits medley - and strip tease - to Stevie Wonder's rousing show-closer "Superstition," the 2012 Billboard Music Awards (May 20) recaptured the non-stop manic energy of its 2011 rebirth. Jam-packed with 16 live performances, the ceremony was broadcast for the second year by ABC from the MGM Grand Garden Arena in Las Vegas.

The Billboard Music Awards won the night for ABC among adults 18-49, according to fast affiliate numbers from Nielsen. The three-hour telecast was watched by 7.4 million total viewers, with a 2.7 share rating in the 18-49 demo. That was enough to handily beat NBC's finale of "The Celebrity Apprentice" (5.6 million viewers, 1.6 share of 18- to 49-year-olds). The telecast was down slightly from last year, when the legendary franchise returned for the first time in five years and averaged 7.9 million total viewers and drew a 2.9 share in the 18-49 demo.

The first award of the evening, top social artist, went to Justin Bieber. In addition to acknowledging mentor Usher and manager Scooter Braun, the teen singer added, "I want to thank all my fans because the Internet is where I got my start." Bieber became the first, but by no means the last, artist to give shout-outs to the fans, whose engagement plays a part in determining the awards themselves. Taking home its own awards six-pack was party duo LMFAO. GoonRock and Lauren Bennett, featured on LMFAO's "Party Rock Anthem," won five awards each. Coldplay and Lil Wayne had big nights as well, with both receiving four BBMAs (see winner's list, page 35). Singer/songwriter Adele won 12 statuettes including top artist and top Billboard 200 artist. (Not on hand to accept, she tweeted her thank you to @billboard. See story, page 37.)

Keeping the energy and the social media chatter buzzing were standout performances by Usher, Bieber and Chris Brown, who won top R&B artist. Brown's five-minute performance of current single "Turn Up the Music" generated 27,713 tweets containing the official hashtag #bbma, according to data from Simply Measured. Bieber, meanwhile, claimed the second- and third-most-talked-about moments for his award win and his performance of new single "Boyfriend."

Also in the mix: a series of special awards and tributes. Katy Perry - who chose the BBMAs for the debut performance of her new single, "Wide Awake" - gave a shout-out to her 91-year-old grandmother Ann Hudson, her date for the evening, upon accepting the Spotlight Award. Taylor Swift made history as the youngest artist to receive Billboard's coveted Woman of the Year Award. And pioneering artist Stevie Wonder was honored with the Icon Award presented by Alicia Keys.

Tribute was also paid to fellow legends who have died in recent months. Natasha Bedingfield honored Donna Summer with a short take on "Last Dance." A reunited Goodie Mob with frontman Cee Lo Green blasted into "(You Gotta) Fight for Your Right (To Party!)" in remembrance of Beastie Boy Adam "MCA" Yauch. Award co-hosts Ty Burrell and Julie Bowen of ABC's "Modern Family" led a moment of silence for Bee Gee Robin Gibb, who died earlier that day.

But bringing the house down was the emotional salute to Millennium Award winner Whitney Houston, featuring John Legend ("The Greatest Love of All") and Jordin Sparks ("I Will Always Love You"). Sparks, who co-stars with the late Houston in the upcoming film remake of "Sparkle," earned a well-deserved standing ovation for her cover of the singer's signature song. (Backstage, as Sparks finished, performers, managers and crew burst into applause.) Whoopi Goldberg presented the award to Houston's daughter Bobbi Kristina Houston-Brown with manager/sister-in-law Pat Houston.

As the house lights dimmed at the MGM Grand Arena, invited guests hustled over to 1OAK at the Mirage for the official BBMAs after-party. Wiz Khalifa celebrated his award win for new artist of the year by performing several songs ("Black & Yellow," "Young, Wild & Free," "Work Hard, Play Hard"). Among the club DJs keeping the dancefloor crowded was guest spinner Swizz Beatz. Spotted either holding court in the various reserved booths or milling around: Cee Lo, LMFAO's RedFoo, Chris Brown, Brandy and her brother Ray J, and Eric Benét.

Awards finalists and winners were determined by chart performance and social and streaming activity as chronicled in Billboard magazine and on during the eligibility period of March 1, 2011-Feb. 29, 2012. The 46 award categories were based on measures provided by Billboard's data partners including sales data shared by Nielsen SoundScan, radio airplay and online streaming monitored and tracked by Nielsen BDS, social media consumption gauged by Next Big Sound and tour grosses tracked by Billboard Boxscore.

Presented in partnership with Chevrolet and the Las Vegas Convention and Visitors Authority, the 2012 Billboard Music Awards was co-executive-produced by Richard Beckman, CEO of Billboard owner Prometheus Global Media, and Don Mischer of Don Mischer Productions.