Last week, the Parents Television Council boycotted radio stations that played "If U Seek Amy," Britney Spears' new single. Did the song have any inappropriate lyrics? Not more so than "Hit Me Baby One More Time." But try saying the line "All of the boys and all of the girls are begging to if you seek Amy" ten times fast. Not only does the lyric not make sense, but "If you seek Amy" sounds suspiciously like "F-U-C-K Me." Oh noes!

And while we got to give props to whomever wrote that song (does anyone really think Britney had any idea what she was singing here??), they weren't onto anything new. Hidden song lyrics have been a staple of the recording industry for the last 40 years. Below, take a look at our favorite examples.

Backmasking

The creepiest way to hide meaning in a song, backmasking involves recording a song or message backwards onto a track on top of another song that is meant to be played forward. Play the song normally, and you'll hear some creepy sounding gibberish, play it backwards and the coded message appears. Fundamentalists were particularly worried about the effect of backmasking on kids in the 70s, believing there was a possibility satanic messages were being subliminally sent into their childrens' brains. Of course, ever since records lost their popularity, technology doesn't really allow for backmasking anymore.

Examples: The Beatles Revolver; Pink Floyd's "Empty Spaces" ("…congratulations. You've just discovered the secret message. Please send your answer to Old Pink, care of the funny farm, Chalfont. "Roger! Carolyn is on the phone!"), Missy Elliot's "Work It", supposedly AC/DC/Judas Priest/every metal band from the 70s.

Anagrams and mnemonics

A less terrifying, more innocuous and widely known way to hide messages in songs is via mnemonics, where you take the first letter of every word and combine it into another phrase. So "Lucy in the Sky with Diamonds" becomes "LSD." An anagram is changing all the letters in word to spell a different word. Thus, Jim Morrison's name in the song "L.A. Woman" becomes Mr. Mojo Risin.

Examples: Beatles' "Lucy in the Sky," Wu-Tang's "Witty Unpredictable Talent and Natural Game," Rush's "Anagram (For Mongo)" Paul McCartney's Memory Almost Full which is an anagram for "For My Soulmate LLM." LLM are the intials of Paul's deceased wife, Linda Louise McCartney. Also Paul McCarthy's "Mister Bellamy" is an anagram referring to his divorce: Mills Betrayed Me.

Hidden Themes

The vaguest of all three genres, Britney's "If U Seek Amy" fits into the category of music that uses either wordplay or sound waves to convey a hidden message. A lot of it is guesswork (Is "Puff the Magic Dragon" really about smoking weed?!) but fun all the same. Aphex Twin uses different frequencies inside their song "Equation" so that when you put it on a Spectrograph it reveals a hidden demon face (in video, skip ahead to 5:27). Since genius musicians can no longer expect fans to buy vinyl for backmasking messages, convincing fans to chart frequencies against time on a Spectrograph is probably the closest that a modern day equivalent to Pink Floyd is going to have.

Examples: "Puff the Magic Dragon," Door's song "Five to One" (refers to Viet Cong to American ratio during Vietnam), Aphex Twin, Radiohead's Web site is full of coded lyrics that presumably "update" fans that have enough time to decipher that bullshit. Lord knows how Thom Yorke finds the hours in a day to make it.