This is a cool lesson, Short and concise but will enable you to play music, inspire you to write music, and just really have fun. You just need a basic understanding of harmony as it relates to harmonizing the major scale. If you have not looked at the Basic Theory post glance over it so that this explanation makes more sense to you. If you know all the chords in the major scale then you are good to go. Let's take a look at the Major scale in G major
Now let's start turning these intervals into chords, but first, let's, number our intervals in Roman numerals.
For purpose of this lesson, major chords will be in stand-alone caps, while minor chords will be caps, followed by the letter (m) in lowercase.
G - Am-Bm-C- D-Em-F# dim-G
I - ii - iii - IV- V - vi - vii dim- I
The four chords that we will extract from the scale will make up the chord progression.
vi -IV -I -V
I IV vi V
Ok, so these chord voicings are slightly different than standard basic voicings. The reason being, Most entry-level students have not yet developed the skill set to change chords quickly. If you notice on the chord grids- your third finger is located on the 3rd fret of the B string and your fourth finger is also on the 3rd fret of the E string. This creates an anchor point that will allow you to make the changes over the G | Cadd9 | Em7 with great ease. When you practice keep those fingers down when playing transitions between the I-IV-vi chords.
If you are a singer-songwriter and the Key of G major is to low in the register just put a capo on, try placing it at the second or third fret, the chord shapes are the same. I'll post a video on this shortly until then get the chord shapes under your fingers.