Psychedelic folk music is a branch of folk music that took the established base characteristics of folk and included psychedelic themes into the instrumentation and thematic ideas. The term first appeared in reference to The Holy Modal Rounders’ 1964 version of Hesitation Blues. Around the same time, folk guitarist John Fahey was experimenting with unusual recording techniques, instruments and guitar tunings which can be heard across his 1966 album The Great San Bernardino Birthday Party, Vol. 4. Another guitarist experimenting in similar ways was Sandy Bull who was combining basic folk concepts with elements from other genres, as well as Middle Eastern and Asian influences.