I love teaching guitar lessons. I teach people with a range of abilities and playing experience and I've given to lessons to students with ages ranging from 4 to over 80.
One of my favourite lessons is when I teach some basic music theory which students can use to help them understand how chord sequences work and how to work out the chords to some songs by ear. They can also use these ideas in their own songwriting.
My starting point for this is to teach them how to play a chord sequence that is fundamental to popular music, the 12 bar blues. As it's name suggests it is a vital ingredient to blues music but it has also been used in rock and roll, country, reggae, pop, soul and just about any style you could think of. Adapted versions of the basic 12 bar blues have been developed which means it's influence spreads ever further from it's original blues beginnings. Despite being well used in countless songs the original chord sequence still turns up in much more modern sounding songs, as we shall see. The best part of teaching this lesson is seeing how amazed people are when they learn they can play thousands of very famous songs with the same chord sequence. It also reminds me how much I love this music!
For the most simple 12 Bar Blues we need just three chords. For a very brief explanation of how we find these chords I explain how the major scale is made up of seven notes. For example the notes that make the C Major scale are;
C D E F G A B
(in the case of C Major these just happen to be all the white notes on a piano)
If we give each note a number to represent where it comes in the scale we end up with;
C D E F G A B
1 2 3 4 5 6 7
12 bar blues uses major chords based on the 1st, 4th and 5th notes of the scale. In the case of C major these would be C, F and G. Below is the chord sequence for 12 bar blues in the key of C Major. Each chord is played for one bar (4 beats.)
C C C C
F F C C
G F C C
Here's the table again but instead of the name of the chord I've used its number in the scale, represented by Roman Numerals because that looks nice.
I I I I
IV IV I I
V IV I I
The cool thing is that we can take the same formula and play 12 bar blues in any key. The notes of the D Major scale are D E F# G A B C# so the I is D, IV is G and V is A. The 12 bar blues in D would look like this;
D D D D
G G D D
A G D D
Here are some songs that use the 12 bar sequence. Although they are in different keys, styles and tempos you might start to spot that the have the same feel. The big give away is the last line of the sequence where we get 1 bar of the V chord, then 1 bar of the IV and then finally two bars of I before it starts again. In many blues and rock and roll songs we get an extra hint from the vocal because the lyric is in a AAB form, meaning first line is sung over the four bars of the I, then repeted over the two bars of IV and two bars of I before finally a pay off line is sung over the run down from V, IV to I.
Here's Big Joe Turner singing the original, blues version of Shake, Rattle and Roll. The song is in the key of Eb. (Start counting the 12 bar from where the vocal comes in, ignore the four bar instrumental intro)
Here's the same song in a rock and roll version by Bill Haley, this time in the key of F (with cleaner lyrics.) Again ignore the intro and start counting from where the vocal starts.
Sometimes we don't get the extra "clue" of having the first line of the lyric repeated but we can still hear the same 12 bar sequence. Here's Jerry Lee Lewis playing a 12 bar in C;
See what I mean? Maybe not but if we could sit and play through the chord sequence together perhaps that would help. Anyway here are some more songs from different decades, in different styles, keys and tempos which all use this basic 12 bar blues format. Sometimes we have an intro before the 12 bar starts, sometimes it's straight in. We may get different endings and stuff but the main idea is always the 12 bar chord sequence.
This one sounds different because we have the stops in the first four bars but if you count along you will find that it's still just four bars of I etc... Little Richard in C;
Here's Paolo Nutini in a much more recent outing with a 12 bar in D major. It's straight in after the drum into and it lasts for the whole song, verse and chorus.
Reggae you say? Still just a 12 bar in E.
Some more for your consideration;
Kansas City Wilbert Harrison C#
Meet Me In The Morning Bob Dylan E
Ball And Biscuit The White Strips E
Folsom Prison Blues Johnny Cash F
Tutti Frutti Little Richard F
Green Onions Booker T and the MGs F
Walkin Blues Eric Clapton G
Matchbox Carl Perkins A
Dizzy Miss Lizzy Beatles A
Let's Stick Together Bryan Ferry A
Goin Up The Country Canned Heat A#