Kay Starr, the self-described hillbilly singer who crisscrossed jazz, country, pop, blues and rock ’n’ roll in the 1950s with hits like “Wheel of Fortune” and “Rock and Roll Waltz,” died on Thursday at her home in Los Angeles. She was 94. The cause was complications of Alzheimer’s disease, her daughter and only immediate survivor, Katherine Yardley, said. Ms. Starr, whose career began when she was a teenager and continued into her 80s, was a rarity: a singer who blossomed in the big-band era of the 1930s and 1940s, hit it big as a pop and country artist, and scored...