Whether they're fresh-faced performers or favorites finally getting their due, the Grammy Awards' choices for the best new artist category tend to run the gamut from popular to obscure. Chart-toppers such as Adele and fun. have taken the prize, as have relative unknowns such as Bon Iver and Esperanza Spalding. With breakout artists such as Kendrick Lamar, Avicii and Macklemore (pictured) in the running, could this be the most mainstream batch of nominees to date? Find out Friday during 'The Grammy Nominations Concert Live!!' (CBS, 10 p.m. ET/tape delay PT).