Loudon Wainwright III details out that the initial line of the initial tune on his 1st album, launched when he was 23, is about ageing: “In Delaware when I was young.” So it is no stretch that the people singer’s 1st album of new compositions in 8 years, Life span Accomplishment, is loosely based mostly on turning 75. It is on sale now. The new tune “How Outdated is 75?,” where he sings, “in five a long time I’ll be 80. I’ll listen to the body fat lady,” is one of Wainwright’s signature mixes of humor and poignant observation. 3-quarters of a century is a milestone, not just simply because…