LESSON 5 

DIATONIC SEQUENCES

 

Ø  This lesson expresses the diatonic sequence and how it can either be an ascending or descending sequence. Ascendant sequences are ascending fifth and ascending parallel 6/3 chords, while the descending parallel 6/3 chord and descending fifth are both descending sequences.

Ø  These sequences can be as little as a motive or can expand as long as a two-bar phrase. These patterns occur one after the other and are transposed either up a step or down a step. The transposition of its intervals is known as the level of transposition. 

Ø  The descending 5th follows a pattern that descends by a cycle of fifths. In a major key, this pattern moves from (I-IV, vii^o-iii, vi-ii, V-I, or I, IV-vii^o, iii-vi, ii-V, I), and in minor keys with usually the leading tone in chord V raised (i-iv-VII-III-VI-ii^o-V-i). The result of this pattern entails the lowering of the second chord by a second.

In this image of the descending 5th sequence, the first two chords C, and F, give an example of how the second chord descends by a 5^th, and the note moves up by a second. This pattern continues throughout the melody as each bar descends by step take note of how each chord descends by a fifth.

https://i.ytimg.com/vi/hFbghCO4U8A/maxresdefault.jpg

Ø  The Pachelbel sequence, easily identified by its chord progression moving down a Fourth and up a second. When it approaches the cadence, it encounters a slight change.

This is an image of the Pachelbel sequence; you will notice how each note descends by a second in the upper voice, while in the bass, the second note descends down by a Fort, and the third up by a second. This pattern continues in the base throughout the melody until it approaches the cadence, where there is a slight change.

https://upload.wikimedia.org/wikipedia/commons/thumb/a/a6/Pachelbel_Canon_harmonie.jpg/300px-Pachelbel_Canon_harmonie.jpg

Ø  The descending parallel 6/3 chord only serves as a sequence and not as a harmonic progression. This type of sequence functions best when just expanding the tonic. All of the chords are only 6/3 that move down by step and can easily arrange as suspense chords, and when they are, it adds a beautiful flavor to it.

In this image of the parallel 6/4 chords, you would notice that they sit between the tonic chords and ascend in the order of vii^o, I, ii, and iii, and they are all 6/4 chords. This function operates similar to the descending parallel 6/4 chord but in the opposite direction.

http://www.sfcmtheory.com/harmony_supplements/chap_18/graphics/18_0007.jpg

Ø  The ascending 5th follows an opposite pattern of the descending 5^th, but rather using a circle of 5^th this time it uses a circle of Fourth ascending.

In this image of the ascending 5^th, notice how the chord progression ascends by a fourth, and everything else moves in the opposite direction of the descending 5^th.

https://www.musictheoryacademy.com/wp-content/uploads/2019/02/Descending-Circle-of-Fifths-Harmonic-Sequence.png

This melody Fly Me To The Moon by Bart Howard is made up of descending fifths, you may want to take note of how chord symbols at each bar follow the circle of fifths.

  

In this video, I am performing the melody above Fly Me to The Moon by Bart Howard. 

This Is A Video of The Pachelbel Sequence

You would be able to view various images of the sequence

Also a brief history of the sequence

How the 3^rd is a part of the development of the sequence

Inversion of the 3^rd  into the 6^th

The syncopated 3^rd

The syncopated 6^th

Involving diminution

Involving chromatics

Tells of how composers employ this sequence in their arrangement

The Parallel 6/3 Chord Sequence

Shows an image of how it's arranged

Expresses the differences between this and other sequences

Show the layout of the chords in the staff turn the inversion

How it is used as 7-6 suspension

It shows and explains the outline of the suspension

How it is used as a 4-3 suspension

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