Nominations for the 37th annual Academy of Country Music Awards were announced Thursday, and Toby Keith and Brooks & Dunn led with six apiece, including album and entertainer of the year. Alan Jackson, Tim McGraw and Travis Trait each had four nominations. Jackson's Sept. 11-themed ballad, "Where Were You (When the World Stopped Turning)," is up for single of the year. Winners will be announced May 22 during a CBS telecast.