You've heard of the twelve bar - it's time to learn what exactly it is.
It is the DNA of popular music. Three chords played in a set sequence over twelve bars.
The twelve bar is an American invention. It was originally taken up by rural blues musicians. The first commercial example was W.C. Handy's 'St Louis Blues'. Then it became the staple of the New Orleans jazz repertoire, the big bands, Chicago blues. And in the fifties, just about every other pop song was written around the twelve bar chord sequence.
It is also the common ground for musicians who want to get to know each other. You might not know the same songs, but you know a twelve bar, and you jam. It's a musical level playing field.
You might not know it but a lot of very familiar songs are twelve bars. Here are twelve:
Can't Buy Me Love
Subterranean Homesick Blues
Making Your Mind Up
Folsom Prison Blues
In The Mood
Sweet Home Chicago
Nick Barraclough has played a few twelve bars in his time. In this programme he talks to bluesologists, a couple of jazzers and a banjo player about why the twelve bar works so well. They illustrate what can be done with this simple sequence and how much fun it can be to mess with it.
Producer: John Leonard
A Smooth Operation production for BBC Radio 4.