An unbelievable story related to this subject. In 1960, I bought an album by a new female jazz vocalist. She was playing piano in a lounge, in order to earn money, to pay for her education as a classical pianist. The owner told her to sing, she protested, he said "Sing or get another job", she sang.
In the beginning, her albums featured 50% vocals and 50% instrumentals. That gal played jazz piano like I had never heard before. Most jazz pianists sound a little like the pianist before them who they admired the most. She was so unique that I place her in a class of one. When you combine classical, back in the woods spiritual, blues and jazz; you get a "gumbo" that cannot be duplicated, "she could bang".
Since singing paid the bills, her albums became exclusively vocal. Only jazz aficionados who are acutely aware of her "banging" piano have every note she played. For the unbelievable part of this story, which only occurred yesterday; go to positive feedback, The Grado reference and Platinum cartridges by Jeffrey Silverstein. While he's "right on" about the jazz vocalist, there are better cartridges for other types of music.