Rihanna and Taylor Swift were two of the key winners at the Billboard Music Awards, which returned after a five-year hiatus with a major dose of star power, featuring Beyonce, U2, the Black Eyed Peas — even First Lady Michelle Obama.

Like many other awards shows, the three-hour Billboard Awards served more as a promotional vehicle for today's top pop stars than a trophy presentation. The show was packed with performances — a piano-levitating Cee Lo Green, a scantily clad Rihanna on "S&M" joined by Britney Spears, a much-bleeped Lil Wayne with Mary J. Blige, and Neil Diamond leading the audience in a sing-a-long to "Sweet Caroline" and "America."

Among Rihanna's wins were for radio artist of the year and top female artist.

Swift won the evening's first award, as top album artist, behind the multimillion sales for "Speak Now." She also won top country artist.

Other award winners included Justin Bieber, Lady Antbellum and the Black Eyed Peas.

Beyonce received a special "Millennium" Award for her career achievements: The 29-year-old phenomenon was lauded in a video by an array of legends and luminaries, including Stevie Wonder, Barbara Streisand, Bono, Lady Gaga and Michelle Obama.

More at entertainment.msn.com.