Lesson 1 - Intervals and triads

Introduction

The basis of the music theory lessons you will find here is an old stenciled manuscript in English named "The jazz guitar theory and techniques". It was the first manuscript I read about jazz guitar theory. The author is unknown to me. I also used other material that I found on the internet, in other good books, and material that I invented myself by combining ideas from other sources. Valuable sources are:

• Levine, Mark, The Jazz Theory Book. Petaluma, California, USA: Sher Music Company, 1995.
• www.jazzguitar.be
• music-theory.ascensionsounds.com

In the lessons lower case letters refer to single notes. Capital letters refer to the root of a scale or chord. For example, a-c-e refers to the single notes which, collectively, make an A minor chord. The cryptic symbol bb refers to the single note B flat.

Intervals

An interval is the relationship between two tones or pitches. The relationship is determined by how far apart the two tones are in the vertical dimension of musical space or staff. If the two pitches are played one after the other, we have a melodic interval; if they are played at the same time, we have a harmonic interval. We measure intervals simply by counting the scale steps, that is, the lines and spaces from one note to the next:

A good way to learn recognize intervals is by dividing them in odd-numbered intervals and even-numbered intervals. Odd-numbered intervals look symmetrical and the notes are on either a line or a space:

For even-numbered intervals one note is on a line and one on a space:

It is a good exercise to take any music sheet and say to yourself loudly the intervals that you see in the song.

Interval quality

Intervals can have five possible qualities. They are listed in the table below, along with their abbreviations, the intervals to which they apply, and some examples of ascending intervals (within the octave) in the key of C major.

Perfect intervals apply only to unisons, 4^ths, 5^ths, and octaves. Major and minor intervals apply only to 2^nds, 3^rds, 6^ths, 7^ths. So we’ll divide learning interval qualities into two groups: group one, the perfect intervals and group two, the major/minor Intervals.

The next table shows all intervals from the unison up to the octave in the key of C. All intervals are determined by the number of half steps between the two notes (#hs). They come with ascending and descending interval examples of tunes from the standard jazz repertoire. Unless otherwise noted, the interval in question is the first two melody notes of the song.

Triads

If three or more pitches are played at the same time, we have a chord. The most simple chords are triads. They are the basic chordal units of traditional harmony. They consist of three different tones: root, 3^rd, and 5^th. The triad occurs in four basic forms: major (1-3-5), minor (1-b3-5), diminished (1-b3-b5), and augmented (1-3-#5). To get a profound knowledge of the fretboard it's important to study triads on the guitar. Every guitarist knows the next basic major and minor barre chords that are thaught in the beginning:

These chords consist of 5 or 6 tones, so they contain doubled tones. They are good for playing solo guitar at the campfire. Next triads consist of just 3 tones: root, 3^rd, and 5^th. So there are no doubled tones. Studying these triads will increase your knowledge of the guitar fretboard, serve as a basis for learning jazz chords, as a basis for slash chords like C/Db, Eb/C, etc, and for playing funk rhythm guitar in a band. And three note chords can be used in your guitarsolo when there's no other chord player in the band: if you want to make clear the harmony, just play a three note chord with your pick, middle finger, and ring finger. While studying these triads be aware of what tone is the root, what tone is the 3^rd, and what the 5^th.

Major triads
Strings 4, 5, and 6

Strings 3, 4, and 5

Strings 2, 3, and 4

Strings 1, 2, and 3

Minor triads
Strings 4, 5, and 6

Strings 3, 4, and 5

Strings 2, 3, and 4

Strings 1, 2, and 3

Augmented triads
Strings 4, 5, and 6

Strings 3, 4, and 5

Strings 2, 3, and 4

Strings 1, 2, and 3

Diminished triads
Strings 4, 5, and 6

Strings 3, 4, and 5

Strings 2, 3, and 4

Strings 1, 2, and 3

Diatonic is the term we use to describe music that uses only the pitches of a particular major or minor scale. Every note in the following excerpt is from the G major scale, therefore it is diatonic: