12 Bar Blues

The 12 Bar Blues is a chord progression that is, not surprisingly, quite common in blues music. However, you can find it in rock, hard rock, and any other style of music with a blues influence. The number of bands that use this structure or derivative forms of it, both blues musicians and other genres, is staggering. Bands from the Beatles to Cream to Van Halen to Led Zeppelin to The Clash have used this structure to some extent. While it is a very simple structure, it can be a very powerful one. The fact it is so common is very similar to the same reason that the minor pentatonic scale is so common. In and of itself, it actually isn’t very interesting, but because it is so simple, a songwriter can do all sorts of things with it that might sound very awkward in a more distinct scale or chord progression.

The basic structure, shown below, for the 12 Bar Blues, not surprisingly, is based around 12 bars. This pattern can be repeated or can transition into a section of the song written with an entirely different chord progression. Since the only chords used are I, IV, and V, you don’t need to worry about switching chord types to stay in key, if you are using full chords in the rhythm. Either all of the chords will be major or minor.

I	I	I	I
IV	IV	I	I
V	IV	I	I

The problem with this structure comes into play when you loop the progression. There are 6 bars in a row without a change from the I chord, and no real distinction to indicate the transition from the 12 bar back to the 1 bar for the listener. The way to solve this is by adding a turn around to the last bar, or occasionally the last two bars of the progression. This can be accomplished quite simply by changing the 12 bar to a V chord as shown below.

I	I	I	I
IV	IV	I	I
V	IV	I	V

While seemingly a very small change, this breaks up the big 6 chord block of I chord bars, while also giving the listener a distinct alert that the progression has looped. It is a very little thing just looking at it written down, but it makes a big difference to what the listener actually hears. In general, sticking with IV and V chords in the turn around is a safe bet, but depending on the song and style of music, there can be a lot of variance in what works for any given song.

The reason this structure can be so widely used in so many distinctively different songs is because it isn’t necessary to just play the same chord for the entire bar of music. While you can do that, and it does work for certain songs, it isn’t a necessity. The chords listed could simply refer to the overall tonality of a particular bar in the song. “Sunshine of Your Love” by Cream is a good example of this idea. The main bars are actually a riff in the tonality of the given bar for most of the song. When the “chord change” comes, they simply switch the riff to a different tonality. Even though the guitar literally isn’t playing chords for those sections, the riff is set up in such a way that the listener still hears the tonality changing.

When first starting out using this structure in writing songs, try to start out simple, and just get to a point where you are happy with the chords and having a turn around that flows well back to the start of the structure or to another chord progression in the song. Once you have that, then you can start doing much more fancy and interesting things with the song. As cool as using riffs are, you still need that underlying structure to hold the song together. That is what makes a song like “Sunshine of Your Love” so effective. It does have a neat, distinctive riff, but that riff is used in such a way that it still conveys the much more basic progression of the song to the listener. It may take some time to get good at being able to get both, but the results are worth it.

Keep on rockin'!