At the earliest moment of rhythm and blues, before there was rock & roll, there was Sister Rosetta Tharpe (1915-1973), an Arkansas native who pioneered gospel and secular popular musical forms all the way back in the 1930s and 1940s. She also played the electric guitar like she was born with it, and could give drama better than a thespian. Elvis Presley, Bob Dylan, Aretha Franklin, John Cash, and many others attested to how important she was to what they did, and really, she's easily one of the most important but least well known 20th century American musical figures. Today is her birthday. Here are two clips of her, from YouTube. I love the first particularly for how she tosses off pitpatter as she strolls inarm-in-arm with her host from the band, to perform for a British audience. "This is the wonderfullest time of my life. Awwww, let me tell you something...!":
And here she is singing "Trouble in Mind," one of the great blues standards.