The Paul Butterfield Blues Band was an influential American blues rock group formed in the early 1960s. Led by harmonica player and singer Paul Butterfield, the band was known for blending electric Chicago blues with rock and soul. They gained prominence for their energetic live performances and groundbreaking integration of black and white musicians during a time of racial division in the U.S. Their innovative sound helped popularize blues music with a wider audience and played a key role in the development of modern blues rock.