[stanron]

There is a kind of balance between being predictable and doing the unexpected.

Patterns, by their nature are predictable. Once a pattern is established, what comes next can be obvious. Of course if everything was predictable it would all become boring, so the occasional detour into the unexpected can be refreshing. There are other, more functional reasons to interrupt patterns. More on this later.

The human ear has great capacity for recognising patterns in sound.

The act of hearing a pattern, recognising it, predicting what happens next and having your prediction confirmed is a kind of glue that keeps you stuck to music.

The simplest patterns are rhythmical. There can also be patterns in melody. In music there is a term used called 'sequence'. (not to be confused with a 'chord sequence') A sequence is a short group of notes whose pattern is repeated starting one note higher or lower in the scale. For example notes 1,2,3 and 1 followed bey 2,3,4 and 2, followed by 3,4,5 and 3 would be a sequence. If you can play that you should hear what I mean by predictable patterns.

There can also be patterns in harmony. The simplest pattern in harmony, by which I mean the simplest pattern in chords, would be repeated seconds. So in the key of C playing playing the chord sequence

C Dm Em F G Am G7 C

would be repeating seconds intervals and also convey the idea of predictable patterns. Incidentally, if anyone is wondering, the G7 at the end is a simple substitution for B diminished. B dim has the notes B, D and F. Add a G and you have G7. In the key of C, G7 is probably the second most important, and functionally useful, chord.

Probably the most used repeated interval is fourths. Baroque music is full of them. (The underlying idea of a fugue is whole melodies displaced in time and separated by a fourth), but that is kind of different.

In the key of C repeated fourth intervals between chords would give you

C F G7(for Bdim) Em Am Dm G C

It makes an interesting chord sequence. Start on the relative minor and you have,

Am Dm G C F G7 Em (or E7 if you prefer) and Am

Repeated fourths are at the heart of what conventional theory calls 'secondary dominants', except that minor chords are made major and flat sevenths are added.

Experiment with repeating other intervals.

Slightly more complex is repeating pairs of intervals. The verse in Hotel California starts with a fifth, in Am it would be Am to E7, then it has a third, E7 to G, a fifth to D and a third to F then a fifth to C. After that it changes but the initial pattern is compelling.

The verse in Ralph McTell's Streets of London and Pachelbel's Canon are both based on the same pair of intervals.

Again they start with a fifth, C to G. then a second, G to Am. This pair of intervals are repeated twice more, making another compelling chord sequence.

So experimenting with pairs of different intervals can be rewarding.

You may have noticed that the last two chord sequences lasted for six bars. One of the curious things about chord sequences is that they usually last for four, eight or sixteen bars. One exception is the twelve bar blues, but that can be seen as three four bar bits joined together. Another exception is Paul McCartney's Yesterday. The verse is seven bars long and it's unexpected end puts emphasis on the word 'Yesterday'. Very clever. And it's a good example of how to break rules. And four, eight or sixteen bars for a chord sequence is as good a rule as you are likely to get.

Chord sequences have to end and when they do end it's called a resolution. A common resolution is chord five to chord one. In the key of C that is G or G7 to C. Its like a musical full stop. Notice in a twelve bar blues that it does not end on chord one. It finishes on chord five, except that it doesn't finish, it leads you back to the start of the sequence and off you go again, you can't stop unless you change the sequence. Ending on chord five is like a musical comma. They are both resolutions but one is final and the other is partial. The last two bars of the chord sequences are resolutions. means of bringing the sequences to a tidy finish.

Patterns in music don't only last for four, eight or sixteen bars. Verse chorus verse chorus is a pattern. Movements in symphonies are patterns. Music is patterns in patterns in patterns etc. in sound. Fascinating stuff.