If you know anything about guitar music theory you know that building chords from the major scale produces the following chord sequence:

1. I major

2. ii minor

3. iii minor

4. IV major

5. V major

6. vi minor

7. vii minor (flat five)

But songs with major two chords are fairly common on guitar. The songs listed below are just a few examples:

“That’ll Be The Day” Buddy Holly – Key of A but includes a B major 2 chord.

“Hey Good Looking” Hank Williams – Key of C but includes a D major 2 chord.

“Patience” Guns and Roses – Key of G (gtr. tuned down 1/2 step to Eb) but includes an A major 2 chord.

“Out of My Head” Fastball – Key of E but includes an F# major 2 chord.

A major 2 chord is actually a key change and stems from the music theory behind a functioning dominant seven chord. A dominant seven chord (which can be referred to as simply 7) is a major chord with a flat seven interval. This occurs naturally on the fifth scale degree in a major scale. The dominant seven 5 chord has a bit of tension that leads to and resolves on 1 (the ‘tonic’ in a major scale). For example, in the key of G a D7 chord leads to and resolves on G. D is said to be the ‘dominant’ of G major. In fact, D can lead to G whether or not the guitar chord actually has the seventh interval in it.

“Hey Good Looking” by Hank Williams is in the key of C and normally has a D minor chord, but the song uses a D major instead which creates a strong pull to G. When playing this song on guitar you’re in the key of C but you’re borrowing the dominant from the key of G in order to produce the dominant pull to and resolution on G. Get it? This is said to be a ‘secondary dominant’ chord and is a composition technique that can be used in any key. So the song examples I used can be explained like this:

“That’ll Be The Day” B major is the dominant of and leads to E.

“Hey Good Looking” D major is the dominant of and leads to G.

“Patience” A major is the dominant of and leads to D.

“Out of My Head” F# major is the dominant of and leads to B.

You can create secondary dominant movement for any chord in a key. Just remember that it’s a type of key change so the scale you play over it with should follow. This is important when learning music theory for guitar