Shave and A Haircut?

You probably think you don't know this 'tune' but you probably do. Years ago i was amazed when my girlfriend-at-the-time used the same knock (as in knock on the front door knock) as i did. Wow! How did you know the family knock? I just assumed it was a local phenomenon. I went around asking people at work- "If you went to a friend's house and knocked on the door- what knock would you use?". Most people's knock was the same. "How did you know that knock?" i demanded- but nobody knew.- and everybody thought i was strange. It'd been passed down from generation to generation- it's origin lost in the mist of time. Even the interweb didn't help- i tried googling:

"knock"
"knock rhythms"
"knock rhythm meme"
"dum-dum-de-dum-dum... dum dum"

Until, one day, Bo Diddley died. I read his obit- and then downloaded some of the dead man's music: "I know a cat named way out Willie- who had a cool little chick named rockin' Millie" etc. There's a link on his wikipedia entry: "Bo Diddley Beat" which then links to a page entitled "Shave and a Haircut". Finally!

Apparently the 1st known occurrence of the tune is from 1899 : "At a Darktown Cakewalk" by Charles Hay. Much later, Milton Berle added the lyrics "Shave and a haircut- shampoo!"- hence the current name of the tune!

Apparently in Mexico, the tune is associated with a profane insult. Whistling the tune is deemed highly offensive and means "Chinga tu madre, cabrón" where cabrón represents the final two notes, and can be used as a response. It can be translated as "Go fuck your mother, you bastard."

I guess there's nothing new about a sticky, memish 'earworm' tune- but why has this one's rhythm become divorced from it's melody and migrated from orchestra to 'front door' (if you consider this an instrument). I wonder if there are any recorded similar migrations?

Who knows if Charles Hay invented the rhythm or adapted it from a preceding door-knock? Or a Charleston rhythm, or Latin American clave rhythm? If he did, he must be an even better song-writer that the sisters who wrote the tune to te ever-popular 'happy birthday to you' in 1893. In 1990 that song was valued at $5 million. (Copyright won't expire until 2030 so remember kids- you can't sing 'happy birthday' or download music- it's illegal.)

What would have happened in , say, 1850 - if you went to your Mexican friend's house for his birthday?: "knock knock knock - let's eat cake". It's hard to conceive of a world without these things.