The big winner at the most recent Grammy Awards was Adele, who went 6-for-6 thanks to the best-selling record of 2011, the critical and commercial darling “21.”

With no such dominant album this year — in fact “21” was 2012’s bestseller — this year’s Grammy race seems more competitive. Nominations for the 55th Grammy Awards, which were announced during an hourlong concert special Wednesday on CBS, went to a variety of acts with main general field categories spanning rock, hip-hop, pop, and R&B.