Well the best place to start would be anything related to the Goa trance scene or rather the electronic movement that started there. Thats where the sound that I am into originated then morphed into what we have today or listen to today. There are plenty of documentaries on the Ytubes but it is a large genre with many many sub categories. rather difficult to say one. This post relates to a variety that I do not really involve myself in. But I will scan the tubes and if I find something relevant i will let you know. Just FYI, I am a rock child.