Here are a couple songs I've found that seem to be influenced by astral travel in one way or another.
http://www.youtube.com/watch?v=w8lRmoObrn0&feature=related (http://www.youtube.com/watch?v=w8lRmoObrn0&feature=related)
http://www.youtube.com/watch?v=yXdwb_lUKvs (http://www.youtube.com/watch?v=yXdwb_lUKvs)
http://www.youtube.com/watch?v=zXHHdCxWGtE (http://www.youtube.com/watch?v=zXHHdCxWGtE)
(this one is about astral traveling through the influence of marijuana, but it's still comin from the same place)
http://www.youtube.com/watch?v=7yfmEDOxWt4&feature=related
This is all about AP