"On the trail of the phantom women who changed American music and then vanished without a trace" In the world of early-20th-century African-American music and people obsessed by it, who can appear from one angle like a clique of pale and misanthropic scholar-gatherers and from another like a sizable chunk of the human population, there exist no ghosts more vexing than a couple of women identified on three ultrarare records made in 1930 and ’31 as Elvie Thomas and Geeshie Wiley. There are musicians as obscure as Wiley and Thomas, and musicians as great, but in none does the Venn...