Powerful, mysterious, unexplainable...
The art of reverse speech/backmasking has been curious to the mind for years. It comes to the point that you hear a song, the you wanna check it out in reverse. Sometimes there is a message, other times its just jibberish. It's something you need an ear for. The 'Stairway To Heaven' one is so popular, it's the prime example of Satanic backmasking. I personally have recorded my voice and reversed it. Needless to say I came up with some bizarre and interesting results. And to answer SHUGA's question, a simple wave editor program like WavePad Sound Editor can get those songs backmasked in a jiffy. Get a hold of more Beatles songs, they tell the downfall of the group in a lot of songs. You won't be dissapointed.