Green Belt: Level 4 Guitar Lessons

Tritone: The Devil's Interval

There is a particularly troublesome interval in the chromatic scale to become acquainted with. Here are a few factoids.

• The Tritone interval is so called, because it is exactly half the number of frets between the bottom and top notes of an octave. The three tones played together are form the tritone sound. Because the overtones in a tritone do not reinforce the overtones in the fundamental tone, the ear has a difficult time discerning whether to move up or down to find the home base. The devil's tone can cause aural vertigo, if overused.
• The devil's tone was not permitted in any medieval church music, being viewed as the antithesis to the so-called perfect intervals.
• Being a dissonant interval, the tritone is seldom dwelt on for long in music, but is often used in modern music as a passing interval in two-part harmonies.

Here again is a friendly reminder not to be too anxious to learn all the other intervals at once. Think of intervals as "vitamin I", which you need to take every day in small doses, but which you should take every day.

Tritone Interval Spelling

This chart shows the spelling of all intervals upward and downward from any starting point. This is important to know when composing music, because if you know the name of one note, then by hearing the interval, you will know the name of the next note you hear by ear.

Notice that some of the tritone spellings have double sharps (##) or double flats (bb) in them. This is because in standard music notation, note names must fit within key signatures, to keep the repeating of written sharps and flats to a minimum. Names of notes are given by counting the natural or fundamental notes, up or down, then adding the accidentals (# or b) on top at the end. In the case of Ab, counting up three naturals gives us B > C > D, which happens to be an augmented 4th, so we stop there. For a diminished 5th, in the case of Ab counting up 4 naturals gives us B > C > D > E, but the pitch is too high, so when we drop two frets lower, it is really a D pitch, but we call it an Ebb to respect the spelling of the 5th.

The Devil's Tone: Augmented 4ths/Diminished 5ths

The Augmented 4th or Diminished 5th interval sounds so strange to our ears, that even though it exists, it is only used sparingly. When it is summoned forth, it can have a surprising or stunning effect on the listener, causing the audience to lose their musical bearing, if only for a moment. It does this because the mind cannot easily perceive which direction they are going relative to home. If dwelt on too long, can erase the notion of home base from the listener's mind. The effect is musical vertigo.

Exercises:

When training your ear, remember: You cannot force your ear to learn. It must happen easily and naturally, and through relaxed repetition over time, rather than cramming all at once. When we try to force the ear to learn, the ear rebels, and closes. Here are some tips to encourage your ear to open up.

• Practice the intervals no more than 10 minutes each day.
• Practice intervals at the beginning of your practice session, when your ear is most open and relaxed.
• Start out by learning the intervals on your instrument, not someone elses.
• Learn the intervals in the order presented in this lesson.
• Play the intervals both on the same string and on different strings. Play them up and down the fretboard, both in order and randomly.
• Sing the note names of each interval as you play it. Sing and play each interval both up and down.
• Play one note in the interval and sing the other. Do this up and down.
• Play and sing each interval both melodically (one note at a time)and harmonically (two notes at a time).
• If your ear gets tired, move onto other things and come back to it fresh tomorrow.