The already-stacked lineup for 'New Year's Rockin' Eve' just got another blast of star power with the addition of Justin Bieber, the Wanted, Psy and others, who will help ring in the 2013 new year with host Ryan Seacrest and headliner Taylor Swift.

Greyson Chance, Ellie Goulding and country star Jason Aldean are the other newcomers to the performance roster. Psy will close out the year by performing one of 2012's most ubiquitous songs, 'Gangnam Style,' in Times Square in New York City, while the rest of the new additions will perform from Los Angeles.

Bieber's spot on the lineup may ease the pain for Beliebers still angry that the singer got snubbed for the 2013 Grammy Awards. The teen star has been showing up at a number of radio concerts across the country this month, and he just announced another leg of the Believe Tour next June.

The show will run for five hours this year, starting at 8PM with a tribute to Dick Clark, the former New Year's Eve host who passed away this year. Previously announced performers include OneRepublic, Carly Rae Jepsen, Flo Rida, Pitbull, Neon Trees, Brandy, and Karmin, while Fergie will serve as host for the L.A. ceremonies.

Watch the 'New Year's Rockin' Eve' 2013 Promo