If you want to learn to play blues guitar then where do you start? Well, the two most fundamental elements of blues guitar playing to learn are the 12-bar blues chord sequence and the blues scale. The most important thing for beginners learning to play blues is to get both of these under your belt.
The 12-bar blues sequence is the fundamental sequence which many blues songs are built on. As it is so fundamental most guitarists know it, and so it is often used as the basis for jam sessions. It can be played with a few variations, but fundamentally it follows this form for each verse (using major chords): Root chord for 4 bars, fourth chord for 2 bars, root chord for 2 bars, fifth chord for 1 bar, fourth chord for 1 bar and root chord for 2 bars. This can be used in any key – for example in the key of A Major, the root chord is A, the fourth chord is D and the fifth chord is E so the pattern is A for 4 bars, D for 2 bars, A for 2 bars, E for 1 bar, D for 1 bar and A for 2 bars.
A number of variations can be introduced in order to make the 12-bar blues sequence more interesting. A common variation is to play the fifth chord for the last bar instead of the root, which gives a good “turnaround” to lead into the next verse. Another common variation is to use 7th chords, particularly to lead into a chord change. For example, you could vary the 12-bar blues in A to be 3 bars of A, 1 bar of A7, 1bar of D, 1 bar of D7, 1 bar of A, 1 bar of A7, 1 bar of E7, 1 bar of D7, 1 bar of A7, 1 bar of E7 or something similar depending on your taste.
So once you’ve learned to play blues guitar rhythm, you’ll want to learn blues guitar lead as well and this is where the blues scale comes in. The blues scale is the fundamental scale on which many blues guitar solos are based and you can play a very convincing blues solo using nothing else but the blues scale.
Technically, the blues scale is the minor pentatonic scale with the addition of a sharpened fourth note, which is known as the “blue note”. So the notes in a blues scale are the root, minor third, fourth, sharpened fourth, fifth and flattened seventh. For example, in the key of A, the blues scale is A, C, D, D#, E, G, A. It’s quite straightforward to learn a blues scale pattern on the guitar fretboard that you can then move around the fretboard depending on which key you want to play on.
Once you have learned the blues guitar scale in at least one fretboard pattern, you’ll want to start using it to create blues solos. Either buy commercial blues guitar backing tracks or record yourself playing a 12-bar blues pattern repeatedly, ideally with a drum machine. Use this to practice playing phrases built from notes in the blues scale. Remember that the root note is fundamental to music, so you’ll often want to start or end phrases on the root. Also, the “blue note” is really a passing note so you shouldn’t usually start or end on that note.
If you want to study blues seriously then it’s a good idea to purchase online blues guitar lessons that give you a structured program of study and introduce you to the many facets of the blues. It’s a fascinating genre that will keep you entertained for years.