NASHVILLE, Tenn.—Tom T. Hall, the singer-songwriter who composed “Harper Valley P.T.A.” and sang about life’s simple joys as country music’s consummate blue-collar bard, has died. He was 85. His son, Dean Hall, confirmed the musician’s death on Friday at his home in Franklin, Tennessee. Known as “The Storyteller” for his unadorned yet incisive lyrics, Hall…