Guitar Lessons and Theory

The Seventh and the Second

The seventh spans seven diatonic scale degrees, the minor seventh contains 10 semitones, the major seventh contains 11 semitones. The pitch ratio of the minor seventh is 9/5 or 7/4 and of the major seventh is 15/8.

The seventh are the first extensions of the diatonic chords:

The sevenths are considered dissonant intervals and they rarely occur at the beginning of the songs. In order to memorize the major seventh, you'll have to keep in mind that only the minor second sounds more dissonant. A classical example is Steve Howe's acoustic solo in The Ancients:

The minor seventh may be heard as a part of the dominant chord but it shouldn't be confused with the diminished fifth of the same chord when practicing. Maybe it's easier to hear a minor seventh as a major second lower than the octave of the first note.

The second spans two diatonic scale degrees, the minor second contains 1 semitone, the major second contains 2 semitones. The pitch ratio of the minor second is 16/15 or 25/24 and of the major second is 9/8 or 10/9. The minor second is also called a semitone and the major second is also called a tone.

They are dissonant intervals. The minor second sounds as the most dissonant interval of all.

There are countless tunes that begin with a second. It's easy to memorize the ascending major second at the beginning of the major scale and the ascending minor second at the end of the major scale:

The Fourth and the Fifth

The perfect fourth spans 5 semitones and has a pitch ratio of 4/3. The perfect fifth spans 7 semitones and has a pitch ratio of 3/2. They are called "perfect" because they occur in both major and minor scales and were always considered as consonances.

We hear the fourth in the opening of a lot of tunes before the root on the strong beat. The anthems are the best example. La Marseillaise starts with a fourth.

On the other hand, a lot of guitar solos start with a fifth. The solo of Stairway to Heaven is a famous example.

The ascending fourth sounds like an answer, while the ascending fifth sounds like a question. The situation is opposite with the descending fourth and fifth. The descending fourth sounds like a question, while the descending fifth sounds like an answer.

It's also easy to hear the fourths and the fifths together as double-stops. The fourth occurs between the fifth and the root of major and minor chords (G - C in C major, for example). The fifth occurs between the root and the fifth of major and minor chords (C - G in C major, for example). They also form the "power chords", so often met in rock.

Between the perfect fourth and the perfect fifth we find the dissonant augmented fourt or diminished fifth, known also as the tritone. It spans 6 semitones and has a pitch ratio of 7/5.

The octave inversion of the perfect fourth is the perfect fifth, while the octave inversion of the perfect fifth is the perfect fourth. The tritone is its own octave inversion because it divides the octave in two equal parts.

It's very easy to hear a tritone. A song that starts with an augmented fourth is Maria from West Side Story. It may be heard in a lot of rock riffs like Metallica's "Enter Sandman", in Hendrix' "Purple Haze", in Dream Theater's "As I Am", etc.

To hear the tritone as double-stop, just think that it occurs between the third and the seventh of the dominant seventh (B - F in the G7 chord, for example).

The Third

The third spans three diatonic scale degrees, the minor third contains 3 semitones, the major third contains 4 semitones. The pitch ratio of the third sixth is 6/5 or 7/6 and of the major third is 5/4.

Chords are formed as succession of thirds. When the interval between the tonic (first degree) and the mediant (third degree) of a chord is a major third the chord is a major chord.

When the interval between the tonic (first degree) and the mediant (third degree) of a chord is a minor third the chord is a minor chord.

The point is to memorize how it sounds. Some examples:

Major thirds from Bernstein's West Side Story:

The riff of Smoke On the Water begins with a minor third:

A descending minor third from Deep Purple's Mistreated:

The diminished arpeggio is a succession of minor thirds:

Beethoven's Fifth opens with a descending major third followed by a descending minor third:

The thirds are often played as double-stops like in Paganini's 24th capriccio:

Learn to hear the difference between major and minor thirds and between major and minor chords. It's one of the most important things in relative hearing.

The Sixth

The sixth spans six diatonic scale degrees, the minor sixth contains 8 semitones, the major sixth contains 9 semitones. The pitch ratio of the minor sixth is 8/5 and of the major sixth is 5/3. 3, 5 and 8 are adjacent numbers of the Fibonacci sequence. So, if we divide the octave by the golden ratio, we'll find ourselves between the minor and the major sixth. Maybe that's why the sixths give a pleasant, harmonic sound.

The major sixth may be found between the 5th and the 3rd of the major triad (G and E in the C-major triad) and between the 3rd and the root of the minor triad (flat E and C in the C-minor triad).

The minor sixth may be found between the 5th and the 3rd of the minor triad (G and flat E in the C-minor triad) and between the 3rd and the root of the major triad (E and C in the C-major triad).

There are countless examples of songs where the sixths are frequently used and that helps to memorize them. My Bonnie begins with a major sixth; G - E.

Mark Knopfler's first solo in Private Investigation starts with a minor sixth; B - G.

The theme in the movie Love Story is full of major and minor sixths; C - E descending, E - C ascending, D - B, C - A, B - #G.

Once you memorized the sixths from the songs, it's easy to hear that jazz and blues musicians often use sixths in their improvisations.

Memory and Relative Hearing

All what was needed to recognize and memorize intervals was that they were given a name. Relative hearing is a question of memory. Once you heard and memorized a specific interval in a certain piece of music, you will recognize it anywhere else.

Let's take the following: MajorSecond.mid. What comes next? Was I thinking about: Sunshine.mid or Funky.mid? The point is: once I heard Cream's "Sunshine of Your Love" and knew it starts with a major second, when I heard "Funky Town", I realized it starts with a major second too.

That's why it's so important to try to play on your instrument all the melodies you can remember. Listen to what you play, think about the intervals.

Another thing to remember should be chord sequences. The most popular chord sequences include the root (I), the fourth(IV) and the fifth(V) chords. The three chords are very easy to recognize in classic blues. Can you recognize them also in another context? Can you recognize them when they are only a part of a more complex chord sequence where they merge with other chords?

The ear, like the eye, has its memory. All you need is to be aware of it.