Billboard Music Awards Remember Whitney Houston, Robin Gibb

Show also pays tribute to late legends Adam Yauch and Donna Summer.

While the Billboard Music Awards were full of upbeat moments, thanks to highly charged performances from Justin Bieber, Katy Perry and more chart-toppers, the show also was somber at times, paying tribute to some of the music industry's brightest stars who died in the months before Sunday's (May 20) broadcast.

While Whitney Houston had the glitziest of the tributes, other late legends from all musical genres also mourned at the show. Right before the broadcast, the tragic news of Bee Gee Robin Gibb's death broke. The pop star died at the age of 62 after a lengthy battle with cancer. While his tribute was short, it was also very sweet, with "Modern Family" star and host Julie Bowen saying, "His voice and the music of the Bee Gees will live on forever."

Just two days before Gibb passed, the Queen of Disco, Donna Summer, died after her own battle with cancer; she was 63. British pop songstress Natasha Bedingfield recalled Summer's influence over her own music. "Donna Summer was a remarkable woman who brought so much light to so many. If we can remember her through her music, this can never really be the last dance," she said before launching into a rendition of Summer's dance-floor anthem "Last Dance."

Whitney Houston's tear-filled tribute was handled by many. Three-and-a-half months after Houston's untimely death in February, comedian Whoopi Goldberg said in her introduction, "I adored Whitney Houston. What all performers want and need and should get is love, and many of us here loved Whitney, and even if you're one of those who didn't show the love to Whitney, now is your chance, because tonight, that's what we're doing: We're going to be giving Whitney the greatest love of all."

Then, John Legend sat at his piano to perform Houston emotional, uplifting ballad, "Greatest Love of All."

Jordin Sparks — Houston's co-star in her final film, "Sparkle" — handled Houston's legend-making "I Will Always Love You." Dressed in a flowing blue and black gown, the singer belted out the track, while Whitney's daughter, Bobbi Kristina, sat in the audience crying.

As the song wrapped, Whitney's sister-in-law Pat Houston and daughter accepted the Millennium Award in her honor. "This is truly an honor. We thank you, Billboard; we thank you, Whoopi, Jordin; we love you, John. But tonight, the one person that should be accepting this award is the one person that Whitney loved most."

"I just really want to say thank you to everyone who supported us through it all," Bobbi Kristina added. "Thank you so much for showing that much love, 'cause she deserved it. There will never be another one, ever. I thank you so much."

The outpouring of love and emotion didn't end there. Adam Yauch, MCA from the Beastie Boys, who died May 4 from his own battle with cancer, also was remembered. Top New Artist winner Wiz Khalifa said during his acceptance speech that the Beasties took hip-hop to new levels. "I just want to thank the Beastie Boys, and we will never forget MCA."

Later on, Cee Lo Green and Goodie Mobb may have been there to perform their own track, "Fight to Win," but afterward, Cee Lo told the room to get their asses up for their own spirited homage to MCA with "(You Gotta) Fight for Your Right (To Party)."

Share your condolences for the four late musical legends in the comments below.