Gayle F. Wald is a professor at George Washington University and the author of Shout, Sister, Shout!: The Untold Story of Rock-and-Roll Trailblazer Sister Rosetta Tharpe and It's Been Beautiful: Soul! and Black Power TV. She was a consultant for the film Godmother of Rock and Roll. Wald lives in Washington, D.C. Follow her on Twitter at @gaylewald.