(Reuters) – Singers Taylor Swift and newcomer Kacey Musgraves on Tuesday led the nominees for this year's Country Music Association awards, one of the genre's top prizes. Swift, 23, and Musgraves, 25, each scored six nominations, followed by husband-and-wife singers Blake Shelton and Miranda Lambert with five nominations each. Country singer and "American Idol" judge Keith Urban landed four nominations along with group Florida Georgia Line. The Country Music Association is a trade organization comprising individuals working in the genre and members vote winners across singing categories. …