Teach Guitar Logo
 Teaching Skills

Music Skills

Business Skills Aspiring Teachers New Teachers Experienced Teachers
Music Skills Music Skills > Snippets of guitar music theory > Critical intervals
Summary: Bite-sized articles cover a number of points about music theory.

Critical intervals

[last snippet] [snippet listing] [next snippet]

Continuing our discussion on the subject of intervals. There are two groups of intervals that seem to be more critical in their effect than the others - these are the 3rd and 7th intervals.

The 3rd interval determines the overall tonality of a key, scale, chord or phrase: major third produces major tonality a minor 3rd produces minor tonality.

If you combine both tonalities you get a very disturbing sound. An excellent example of this is the 7#9 chord which features strongly in many of Jimi Hendrix' classic songs. The formula for this chord is 1 3 5 b7 #9 The major 3rd is obvious enough, but the minor 3rd is disguised as #9(Remember the 9th note is the same as the 2nd and if you sharpen a 2nd you'll get the same note as if you'd flatted a 3rd!)

Blues and Rock 'n' Roll licks rely heavily for their effect on using the transition from minor to major 3rd. Check out this simple blues lick in G; if you were playing against a G major chord you would play this:


i.e the final note is a B (major 3rd in the key of G)

But if you were playing this lick against a Gm chord you would make sure you ended the phrase on the Bb (minor 3rd in the key of G):

Try it out!

[last snippet] [snippet listing] [next snippet]

Related pages
 Look up music terms
Products from TeachGuitar.com

How to Make a Living Teaching Guitar
by Nick Minnion
 Read More
 Order Information

Fifty Flexible Lesson Plans for Teaching Guitar
by Nick Minnion
 Read More
 Order Information

How to Increase Your Income from Teaching Guitar
by Nick Minnion
 Read More
 Order Information

You Can Play GuitarYou Can Play Guitar
Instructional books and videos.
 Go to site

TeachGuitar Forums

-  Guitarists' Dictionary
- Resource Exchange Library
- Guitar Teacher's Forum


 About Us
 Contact Us
 Nick Minnion