I've been listening to Led Zeppelin backwards and let me tell you, it's the work of the devil.
Well, I should let other people tell you that; Believers will do so anyway. Yet it's the people in the middle that concern me the most, those who are too easily swayed by a stunning coincidence.
Michael Shermer, founder of the US Skeptics Society (and a former fundamentalist Christian), gave a talk for TED, an annual US conference for the "spreading of ideas".
The talk, available here on TED.com and here on LiveLeaks.com, in the course of debunking a few junk beliefs, showed how and why people often believe rubbish. A few examples he gave of those reasons:
1) People notice the "meaningful" results and ignore the failures - eg a US company sells a dowsing rod for detecting marijuana. If it can "occasionally" prove successful in finding it in high school lockers, administrators may be duped.
2) Taking something on face value without asking "what's the most plausible explanation" with all available evidence - viz crop circles.
3) Untestable explanations for existing events or outcomes - viz miracles, creation, divine intervention. (Contrast this with untested reports of individual happenings.)
4) Reading meaning into random patterns - eg seeing Mother Teresa in the shape of a bun.
That last point was the most interesting, and perhaps one of the most overlooked type of credulence-inducing phenomena. The brain has a natural tendency to interpret what one sees or hears. Where the data is incomplete, the mind can fill in the gaps. If a picture of Mars, or tree bark, or sandwich contains random patterns that are suggestive of something else, a little nudge can help convince some people - squint more, for example (it reduces even more the received data), while someone tells you what it is you're looking for. Does it look more like the Virgin Mary - or Jane Russell? Since more mysticism is attached to the former, the latter is "seen" less often.
But the most amazing example from Shermer was a section of Stairway to Heaven played backwards. When he first did this, I could hear the word Satan - but that was because I was listening for something, having been primed by Shermer - and also having heard of people claiming devil messages encoded backwards in music.
Still, I wasn't prepared for playback the second time, when Shermer put up a specific set of words to accompany. What a match! (once my mind was guided.)
How could Led Zep possibly record something that made sense backwards, yet was so musically integral in the forwards direction that no doctoring could be detected? That must take genius. Or Satan.
It's a bit tragic then, that part of the backwards lyric included '666'. The number of the beast? Not quite. Although popular culture has come to associate that number with the devil, more recent research has found the earliest reference to the number in the Book of Revelation gave it as 616.
Hold on, isn't that all a trick by Satan to mislead us?
Well, by this point people are simply going to believe what they want to believe.
Interestingly, there's a holy roller who interprets those same backwards words somewhat differently, on this video - start at 7.53 if you don't want to wade through the lot. A good illustration of the power of suggestion to help fill in the "data" gaps; it also illustrates that the desire to locate (create) interpretations is the driving force: - if not for Led Zeppelin, those preachers would be finding satan elsewhere - as they do.
(Thanks to Bill for the original web reference. It made my day to listen to that Led Zep backwards while my brain was guided by the printed "lyrics". Sad satan will never be the same.)