Today is a big day for Beatles fans: the band's entire catalog is being reissued in digitally remastered form, and the video game "The Beatles: Rock Band" is also set for release. And what better day than 09/09/09, considering the band's love of the number nine (enneaphilia?), from "The One After 909" to "Revolution No. 9." In honor of the latest wave of Beatles nostalgia, I've been mulling over a bit of nonsense from the fertile mind of John Lennon: the timeless chant heard in "I Am the Walrus," "Goo goo ga joob."

Originally released as the B-side of "Hello Goodbye" and as a track on the Magical Mystery Tour album in November 1967, "I Am the Walrus" has been an endless source of lyrical debate. And that's just how Lennon wanted it: he reputedly constructed the song to be as confusing as possible, in order to keep the Beatle-ologists busy. The chorus of the song goes, "I am the eggman, They are the eggmen, I am the walrus, Goo goo ga joob." The "walrus," Lennon later confirmed, was an allusion to the Lewis Carroll verse, "The Walrus and the Carpenter," from the children's classic Through the Looking-Glass. It's believed that the "eggman" is a nod to the character of Humpty Dumpty in the same book. But what of "goo goo ga joob" (also transcribed as "goo goo goo joob" or "goo goo g'joob")?

One widely circulated tidbit is that Lennon was inspired by James Joyce's Finnegans Wake while writing the song. This would fit nicely with the Lewis Carroll homage, since Humpty Dumpty figures in Joyce's stream-of-consciousness masterpiece as well. (Finnegan's fall from a ladder resonates with the fall of Humpty Dumpty and the Fall of Man.) According to Beatles lore, "goo goo ga joob" are "the last words uttered by Humpty Dumpty before his fall." This was a popular notion among the conspiracy theorists who were convinced that Paul McCartney had died in a mysterious accident and looked for clues to his demise in Beatles lyrics.

The only problem with the Joycean theory is that "goo goo ga joob" does not actually appear in Finnegans Wake. The closest approximation in Joyce is "googoo goosth," which doesn't quite have the same ring to it. There's also no evidence that Lennon was actually reading Finnegans Wake at the time, so the imprint of Joyce is not nearly as clear-cut as that of Lewis Carroll.

Around the same time as "I Am the Walrus," a very similar nonsense refrain cropped up in another pop song, Simon & Garfunkel's "Mrs. Robinson." Songwriter Paul Simon penned the lyrics, "Coo coo ca-choo, Mrs. Robinson, Jesus loves you more than you will know." The song was released too late to have been an influence on Lennon: though a brief early version of "Mrs. Robinson" appeared in the movie The Graduate in late 1967, the full song with "coo coo ca-choo" didn't show up until the Simon & Garfunkel album Bookends in April 1968. So the influence could very well have flowed the other way, with Simon making a subtle gesture to the then-new Beatles song.

Both Lennon and Simon, I believe, were at least indirectly influenced by another pop-cultural source: the catchphrase of the 1930s cartoon bombshell Betty Boop, "boop-oop-a-doop." It's got the same metrical cadence as "goo goo ga joob" and "coo coo ca-choo," and is similarly reminiscent of infantile babbling. The provenance of "boop-oop-a-doop" is itself the subject of much dispute. The singer Helen Kane claimed that she was the originator of the phrase, and in 1934 she sued Betty Boop's creator Max Fleischer for $250,000 in damages. Kane was famous for using "boop-oop-a-doop" in such tunes as "I Wanna Be Loved By You" (memorably covered by Marilyn Monroe in Some Like it Hot), sung in her distinctively babyish voice.

Kane didn't win her lawsuit, because during the trial it was revealed that she had based her "boop-oop-a-doop" on the stylings of an African-American entertainer named Baby Esther, popular at Harlem's Cotton Club in the late 1920s. The New York Times reported that Baby Esther "had interpolated words like 'boo-boo-boo' and 'doo-doo-doo' in songs at a cabaret here in 1928 and that Miss Kane and her manager had heard her there." A recording of Baby Esther's act played in the courtroom was enough to doom Helen Kane's claims to originality.

I haven't been able to track down a recording of Baby Esther, so I don't know if her "boo-boo-boo" and "doo-doo-doo" have the same syncopated spunk as the "boop-oop-a-doop" of Helen Kane and her cartoon alter ego Betty Boop. But we should not forget these pioneers in stylized baby talk who laid the groundwork for the inspired babble of "I Am the Walrus."

(Enjoy some YouTube clips of Helen Kane, Betty Boop, and Marilyn Monroe for the full "boop-oop-a-doop" experience.)