Percy and his brother, clarinetist Willie Humphrey, became well-known from the 1960s on for their playing in the erratic but enjoyable Preservation Hall Jazz Band. Percy, whose other brother was trombonist Earl Humphrey (1902-1971), was never a major musician, but he played his simple melodic leads with sincerity. He gained his initial recognition working with New Orleans brass bands, including the Eureka Brass Band.