So, what is the 12 bar blues? Well, simply stated, it's a predetermined sequence of chords that lasts for 12 bars or measures. Each measure is normally four beats long. When jamming or playing a song, this predetermine sequence is repeated over and over until the end. The chords that make up the sequence are three, the tonic, the sub dominant, and the dominant. a simpler way of stating this is the one chord, the four chord and the five chord using Roman numerals.
Using Roman numerals is very smart because you can reuse your notations independently of which key you're playing. This also means that you don't need to remember the dominant in every key to change the key We simply change the harmonica. In this course, we will be working in G major. And in G major, the one chord is G, the four chord is C, and the five chord is D. I tell you this for completeness, but don't sweat it. If you don't remember, you can always look it up later. So now on to the sequence of the chords, we start with four measures of the one chord.
We then change the two measures of the four chord. Then we go back to two measures of the one chord. Then we go for one measure to the five chord, one measure of the four chord and we end with two measures of the one chord. And that completes the 12 bar blues. Actually, it's not 100% true that we'll end with two measures of the one chord Normally, in the last bar, we actually go to the five chord just briefly for one or two beats. And that's what's called the turnaround.
And it's a signal to the rest of the musicians that we're going to repeat everything again. In the resource section, you will find a PDF outlining the 12 bar blues. I suggest you download it and get familiar with it. Now that you know what the 12 bar blues progression is, you might wonder if it will make all your songs and all your jams sound the same? Well, the simple answer is no. By varying the key, the tempo, the groove, the start of the song and the end of the song, you won't even think about that you're using the 12 bar blues over and over again.
The real power of the 12 bar blues is that you can communicate everything to your fellow musicians just by saying 12 bar blues key of G, shuffle and then count them in. After that, they know exactly what to do. If you want to be a little bit more advanced, you can instruct the band to start somewhere else down from the bar one. There is additional information on how to do this in the resource section.