So far, we've been using intervals primarily to reduce learning effort.
After today, I'll be talking about intervals in their applied musical context. Over a few more lessons, we'll take a look at structuring music, factors that contribute to a musical style, creating tonality through intervals, phrasing, and chromaticism.
ReviewThe current motivation for learning these shapes is to reduce the overall effort of learning chords and scales, simply because doing this purely based on pitch names is way harder.
By name, here are a few major triads: C (C, E, G), Eb (Eb, G, Bb), A (A, C#, E). There are twelve of these. By intervals: (1, 3, 5). There is one of these. By name, you have to locate these wherever, and then maybe we next add in chord inversions: C in first inversion (E, G, C) and so on. That's another twelve patterns of different notes to learn. By intervals: (3, 5, 1).
Since there are so few interval shapes, compared to note combinations, we can visualise these easily, once we know the shapes, to locate the chord and scale components in any key.
Where we're heading with a knowledge of intervals.Armed with the above visual knowledge, and backed up by developing aural skills at recognising the sound of intervals over time and practise, we can then learn how to use intervals to enforce, or contradict, the sense of where the music is heading, hence to emotionally affect our audience.
In the next lesson, we'll start digging into this. For example, when we listen to a (section of a) song, usually one pitch seems to stand out the most, and the musical activity (chord progression, melody) collaborate to make this happen, wandering away from it for contrast, and wandering back to it to remind the listener.
Think of a simple 12 bar blues in E. We may not know the pitch is an E, but we can hear it's the basis around which the song is evolving. If that exact same song is played next day in G, chances are most people won't recognise any different ... because all the relationships between the chords and melody are maintained ... the same intervals are in use, just created from a different start point (G rather than E).
But if the vocalist has a sore throat, and struggles in G, he may be unable to sing some of the melody correctly and sing out of tune, and now we do notice something is wrong ... the interval relationships in the melody against the start point, G, have been changed inadvertently by the singer.
The theoretical term for all this collaboration is "establishing the tonality" ... using a set of intervals (a scale) built off a particular pitch (for example, G), in such a way as to focus the listener's attention on that pitch ... to establish that pitch as the "tonal centre," or "key note."
If we know how to use intervals to do this, we also know how to use intervals to blur or hide what's going on ... to make the listener aware something unexpected is happening. Perhaps we're actually gradually changing over to a different key, and during this change, things are pretty ambiguous.
Something to be aware of from the beginning of learning about music is that composers and improvisers rarely stick to exactly what's expected, what's "correct," and love ambiguity and surprise. We'll look at this later.
Interval shapesI strongly recommend that you know the shapes for octave, b3, 3 and 5 from the last lesson. These are your bedrock, and we'll see are critical to tonality. Here are all the shapes now.
Aide memoiresThe following two items have helped me many times. The first is the simple fragment (1, 2, 3, 4, 5) that I used to refer to as a convenient miniature roadmap on the neck. The second is finding the nearest 5 from a given 1. With that, then the fragment is nailed down "at the top", at the 5. Hence the remaining intervals (1, 2, 3, 4) are at your fingertips. These are both further aids to reinforcing your knowledge of scale and chord shapes, and transforming the guitar neck from an unstructured sea of notes into the structured instrument that it is.
Here is the fragment as two shapes, on the left of the diagram. The upper shape is an adjustment of the lower shape, due to the difference in tuning of the G, B string pair. On all string pairs apart from G, B the shape shown on the E, A string pair can be used everywhere, just position the red pitch (1) where you want.
The right hand side of the above diagram shows how to visually locate the 5 (the blue circle) below a given 1. This is based on the observation that the octave above 1 is twelve semitones higher, that the 5 above 1 is seven semitones higher, and hence from that 5 to the octave of 1 is another five semitones (7 + 5 = 12). Therefore, to find the 5 below a given 1, use the shape for five semitones, with that 1 being the upper pitch in the interval shape. And of course, you have the b5 and #5 either side (a semitone lower or higher than the 5).
ExerciseSuppose you're soloing using the A minor blues scale (1, b3, 4, b5, 5, b7) over an A major blues. Suppose you've played the pitch A at the 7th fret on the D string. Use the second tip above to find the b5. Then play the 5 and use the first tip (the fragment) to descend down 5, 4, 3, 2, 1 to add some contrasting major feel, into the line.
That's it for today. Hope you enjoyed it. As usual, either message me or leave a comment here, if you need any clarifications. This is the pragmatic stuff out the way now. We can move on using this knowledge to make music.