2015 Billboard Music Awards: Sam Smith, Taylor Swift Lead the Way

This year's Billboard Music Awards nominees features some regulars and some surprising acts.

The artists with the most nominations are Taylor Swift and Sam Smith with each landing nominations for top artist and top Billboard 200 album and Hot 100 song.

Sam Smith is behind Swift with 13 nominations, and the singers will battle one another in eight categories, including the night's biggest prize, top artist. Ariana Grande, One Direction and Katy Perry are also up for the top award.

One Direction, Ariana Grande and Katy Perry are up against Swift and Smith for top artist.

Sam Smith will compete with Ed Sheeran, Drake, Pharrell Williams and Justin Timberlake for Top Male Artist, while Swift is up against Grande, Perry, Azalea and newcomer Meghan Trainor for Top Female Artist.

One surprising act in the upper ranks of the awards is the pop-a-cappella group Pentatonix, up for Billboard 200 album against more traditional acts such as Ed Sheeran and Maroon 5.

The 2015 Billboard Music Awards, which honors the year's most successful music artists in 41 categories, will broadcast live on May 17 from the MGM Grand Garden Arena in Las Vegas, Nevada on ABC network.

Billboard Music Awards finalists are based on key fan interactions with music, including album and digital songs sales, radio airplay, streaming, touring and social interactions on Facebook, Twitter, Instagram, YouTube, Spotify and other popular online destinations for music.

These measurements were tracked from March 10, 2014 through March 8, 2015 by Billboard.

Who do you think will win the top awards?