Billboard Music Awards: What to Expect From the Star-Studded Show

From the performances to the nominations, get all the details here.

— -- The competition is stiff for the 2015 Billboard Music Awards, airing this weekend on ABC, live from the MGM Grand in Las Vegas.

"I love the Billboard Awards," gushed Swift in a clip from Countdown to the 2015 Billboard Music Awards. "I always have a great time and I love the fact that the awards are, are based on what the fans have actually decided to invest in and buy."

While Swift isn't performing this year, she'll make a huge impression on the telecast: It'll start with her star-studded video for "Bad Blood," which features the likes of Lena Dunham, Jessica Alba, rapper Kendrick Lamar, Ellen Pompeo, Mariska Hargitay, Hailee Steinfeld, Karlie Kloss, Paramore's Hayley Williams, Ellie Goulding and more, all playing characters with names like "Luna," "Justice," "Knockout," "Destructa X" and "Dilemma." Swift herself is portraying someone named "Catastrophe," and all we know is that there will be fighting involved.

In Countdown to the 2015 Billboard Music Awards, Swift explained the thinking behind the video's concept.

"Let's have them play assassins in a music video," she said. "They are metaphorically killing it. They are also playing killers."

Swift, Azalea and Trainor are all up for the only fan-voted category: the Billboard Chart Achievement Award presented by Samsung, recognizing each woman's huge chart success in the past year.

The BBMAs will be hosted by rapper/actor Ludacris and model and host Chrissy Teigen. Ludacris told ABC News that of all this year's nominees, he was most impressed by the success of one particular singer.

"I think every year we have someone who is just like a standout person in music and I think Sam Smith takes that cake for this year," he said. "I think he said it best when he won his Grammy. He was like, once he just started being completely honest and pouring his heart out, then everyone started gravitating toward his music and it shined. And I’m extremely happy for him."

The rapper and "Furious 7" star also noted what makes the Billboard Awards different from all the other awards shows out there: They reward the artists and the music that have been most successful on the Billboard charts by measuring actual data: album and digital songs sales, radio airplay, streaming, touring and social interactions.

"It’s based off the charts and it’s not like you can say you don’t know how someone won or certain things like that. So it is based off the people," he explained.

The 2015 Billboard Music Awards air Sunday night, May 17, live on ABC, starting at 8 p.m. ET.

Here are the nominations:

Top Artist

  • Ariana Grande
  • One Direction
  • Katy Perry
  • Sam Smith
  • Taylor Swift
  • Top Billboard 200 Album

  • Maroon 5, V
  • Pentatonix, That's Christmas to Me
  • Ed Sheeran, X
  • Sam Smith, In the Lonely Hour
  • Taylor Swift, 1989
  • Top Male Artist

  • Drake
  • Pharrell Williams
  • Ed Sheeran
  • Sam Smith
  • Justin Timberlake
  • Top Female Artist

  • Iggy Azalea
  • Ariana Grande
  • Katy Perry
  • Taylor Swift
  • Meghan Trainor
  • Top Hot 100 Song

  • Iggy Azalea feat. Charli XCX, "Fancy"
  • John Legend, "All of Me"
  • Sam Smith, "Stay with Me"
  • Taylor Swift, "Shake It Off"
  • Meghan Trainor, "All About that Bass"
  • Top New Artist

  • Iggy Azalea
  • 5 Seconds of Summer
  • Hozier
  • Sam Smith
  • Meghan Trainor
  • Top Duo/Group

  • 5 Seconds of Summer
  • Florida Georgia Line
  • MAGIC!
  • Maroon 5
  • One Direction
  • Top Billboard 200 Artist

  • One Direction
  • Pentatonix
  • Ed Sheeran
  • Sam Smith
  • Taylor Swift
  • Top Radio Songs

  • John Legend
  • Maroon 5
  • Ed Sheeran
  • Sam Smith
  • Taylor Swift
  • Top Touring Artist

  • Lady Gaga
  • Rolling Stones
  • One Direction
  • Katy Perry
  • Justin Timberlake
  • Top Social Artist

  • Justin Bieber
  • Miley Cyrus
  • Ariana Grande
  • Taylor Swift
  • Selena Gomez
  • Top Streaming Artist

  • Ariana Grande
  • Nicki Minaj
  • Iggy Azalea
  • Taylor Swift
  • Meghan Trainor
  • Top R&B Artist

  • Beyoncé
  • Chris Brown
  • John Legend
  • Trey Songz
  • Pharrell
  • Top Digital Songs Artist

  • Iggy Azalea
  • Ed Sheeran
  • Sam Smith
  • Taylor Swift
  • Meghan Trainor
  • Top Rap Artist

  • Iggy Azalea
  • J. Cole
  • Drake
  • Nicki Minaj
  • Rae Sremmurd
  • Top Country Artist

  • Jason Aldean
  • Luke Bryan
  • Florida Georgia Line
  • Brantley Gilbert
  • Blake Shelton
  • Top Rock Artist

  • Bastille
  • Coldplay
  • Fall Out Boy
  • Hozier
  • Lorde
  • Top Latin Artist

  • J Balvin
  • Juan Gabriel
  • Enrique Iglesias
  • Prince Royce
  • Romeo Santos
  • Top Dance/Electronic Artist

  • Avicii
  • Clean Bandit
  • Disclosure
  • Calvin Harris
  • Lindsey Stirling
  • Top Soundtrack

  • "The Fault in Our Stars"
  • "Fifty Shades of Grey"
  • "Frozen"
  • "Guardians of the Galaxy Awesome Mix Vol. 1"
  • "Into the Woods"
  • Top R&B Album

  • Beyoncé, Beyoncé
  • Chris Brown, X
  • Michael Jackson, Xscape
  • John Legend, Love in the Future
  • Pharrell Williams, G I R L
  • Top Rap Album

  • J. Cole, 2014 Forest Hills Drive
  • Drake, If You’re Reading This It’s Too Late
  • Nicki Minaj, The Pinkprint
  • Iggy Azalea, The New Classic
  • Eminem, The Marshall Mathers LP 2
  • Top Country Album

  • Jason Aldean, Old Boots, New Dirt
  • Garth Brooks, Man Against Machine
  • Luke Bryan, Crash My Party
  • Brantley Gilbert, Just As I Am
  • Miranda Lambert, Platinum
  • Top Rock Album

  • AC/DC, Rock or Bust
  • The Black Keys, Turn Blue
  • Coldplay, Ghost Stories
  • Hozier, Hozier
  • Lorde, Pure Heroine
  • Top Latin Album

  • Juan Gabriel, Los Dúo
  • Enrique Iglesias, Sex and Love
  • Romeo Santos, Formula Vol. 2
  • Santana, Corazon
  • Marc Anthony, 3.0
  • Top Dance/Electronic Album

  • Avicii, True
  • Disclosure, Settle
  • Calvin Harris, Motion
  • Skrillex, Recess
  • Lindsey Stirling, Shatter Me
  • Top Digital Song

  • Mark Ronson feat. Bruno Mars, “Uptown Funk!”
  • Sam Smith, “Stay with Me”
  • Taylor Swift, “Shake It Off”
  • Meghan Trainor, “All About That Bass”
  • Pharrell Williams, “Happy”
  • Top Radio Song

  • John Legend, “All of Me”
  • MAGIC!, “Rude”
  • Nico & Vinz, “Am I Wrong”
  • Sam Smith, “Stay with Me”
  • Pharrell Williams, “Happy”
  • Top Streaming Song (Audio)

  • Iggy Azalea feat. Charli XCX, “Fancy”
  • Hozier, “Take Me to Church”
  • John Legend, “All of Me”
  • Sam Smith, “Stay with Me”
  • Tove Lo, “Habits (Stay High)”
  • Top Streaming Song (Video)

  • Idina Menzel, “Let It Go”
  • Bobby Shmurda, “Hot Boy”
  • Taylor Swift, “Blank Space”
  • Taylor Swift, “Shake It Off”
  • Meghan Trainor, “All About That Bass”
  • Top R&B Song

  • Chris Brown feat. Lil Wayne, French Montana, Too $hort & Tyga, “Loyal”
  • Jason Derulo feat. 2 Chainz, “Talk Dirty”
  • Jeremih feat. YG, “Don’t Tell ‘Em”
  • John Legend, “All of Me”
  • Pharrell Williams, “Happy”
  • Top Rap Song

  • Iggy Azalea feat. Charli XCX, “Fancy”
  • Iggy Azalea feat. Rita Ora, “Black Widow”
  • Big Sean feat. E-40, “I Don’t F**k with You”
  • Nicki Minaj, “Anaconda”
  • Bobby Shmurda, “Hot Boy”
  • Top Country Song

  • Jason Aldean, “Burnin’ It Down”
  • Luke Bryan, “Play It Again”
  • Sam Hunt, “Leave the Night On”
  • Florida Georgia Line feat. Luke Bryan, “This Is How We Roll”
  • Florida Georgia Line, “Dirt”
  • Top Rock Song

  • Bastille, “Pompeii”
  • Coldplay, “A Sky Full of Stars”
  • Fall Out Boy, “Centuries”
  • Hozier, “Take Me to Church”
  • Paramore, “Ain’t It Fun”
  • Top Latin Song

  • J Balvin feat. Farruko, “6 AM”
  • Enrique Iglesias feat. Descemer Bueno & Gente de Zona, “Bailando”
  • Romeo Santos, “Eres Mía”
  • Romeo Santos feat. Drake, “Odio”
  • Romeo Santos, “Propuesta Indecente”
  • Top Dance/Electronic Song

  • Clean Bandit feat. Jess Glynne, “Rather Be”
  • Disclosure feat. Sam Smith, “Latch”
  • DJ Snake & Lil Jon, “Turn Down for What”
  • Ariana Grande feat. Zedd, “Break Free”
  • Calvin Harris, “Summer”
  • FAN VOTED AWARD

    Billboard Chart Achievement Award presented by Samsung

  • Iggy Azalea
  • Taylor Swift
  • Meghan Trainor