Paul Vaughn Butterfield was an American blues harmonica player, singer and bandleader. After early training as a classical flautist, he developed an interest in blues harmonica. He explored the blues scene in his native Chicago, where he met Muddy Waters and other blues greats, who provided encouragement and opportunities for him to join in jam sessions. He soon began performing with fellow blues enthusiasts Nick Gravenites and Elvin Bishop.
In 1963, he formed the Paul Butterfield Blues Band, which recorded several successful albums and was popular on the late-1960s concert and festival circuit, with performances at the Fillmore West in San Francisco, the Fillmore East in New York City, the Monterey Pop Festival, and Woodstock. The band was known for combining electric Chicago blues with a rock urgency and for their pioneering jazz fusion performances and recordings. The band was also among the first racially integrated blues groups. After the breakup of the group in 1971, Butterfield continued to tour and record with the band Paul Butterfield's Better Days, with his mentor Muddy Waters, and with members of the roots-rock group the Band.