Listen to Proof of Principle (Progressive Psychedelic Goa Mix) online. Proof of Principle (Progressive Psychedelic Goa Mix) is an English language song and is sung by Psilocybian. Proof of Principle (Progressive Psychedelic Goa Mix), from the album 101 Trance Hits - Best of Progressive Psychedelic Goa, Acid House, Tech Trance, Fullon Psy, Rave Music Anthems, was released in the year 2013. The duration of the song is 7:40. Download English songs online from JioSaavn.