Amazingly, more addition acts will be announced in the coming days.
This year's ceremony will feature a new category, electronic dance music, as well as awards in genres including pop/rock, country, rap/hip-hop, soul/R&B, alternative, adult contemporary, Latin and contemporary inspirational. Rihanna and Minaj lead the nominations with four each.
Other artists with multiple nominations include Drake, Justin Bieber, Maroon 5, One Direction and Usher with three each, and Underwood, Chris Brown, fun., Gotye, J. Cole, Katy Perry, Kelly Clarkson, Luke Bryan and Pitbull with two apiece.
For the sixth year, winners will be decided by online fan voting. The show will air on ABC live from Los Angeles' Nokia Theatre at 8 p.m. ET/PT on Saturday, Nov. 18.