The Chicago blues sound is strong in Butterfield's playing. His single-note line harmonica solos recall the brisk, flowing melodic style of Sonny Boy Williamson II (“Don't Start Me to Talkin'”), and he also absorbed lessons in the art of the slow burn from the likes of James Cotton, whose long, vibrato textures on “Blues In My Sleep (‘Fore Day Blues)” point toward some of Butterfield's most joyous jam-session work.