[rbanffy]

Sound has been used to induce trance and mystical experiences since very early in history. Usually it involves religion, which is usually far more damaging than music as it demands the suppression of critical thinking.

I can tell you that http://www.youtube.com/watch?v=en1asB1haQM was an interesting experience (in particular the transition that starts at 1:40) sitting down with volume in moderate levels on ordinary earbud-style phones. Lying down in sort-of sensory deprivation, it could be more so.

BTW, I would like to share a heavier drug I used at a local TED conference. Enjoy it while it's legal:

http://www.tedxsaopaulo.com.br/vitor-araujo-sub/