The answer is Alain Locke.
William Grant Still was a prominent African American composer and conductor, known for his contributions to classical music and opera, but he was not the editor of "The New Negro."
Florence Price was an African American classical composer and pianist, recognized for her symphonies and other compositions, but she was not the editor of "The New Negro."
Alain Locke was a philosopher, writer, and educator, and he is best known for editing "The New Negro," an anthology that played a significant role in the Harlem Renaissance by promoting African American culture and literature.
Margaret Bonds was an African American composer and pianist, known for her work in classical music and her collaborations with Langston Hughes, but she was not the editor of "The New Negro."