What are Sequences in Music?

A sequence is the “more or less exact repetition of a passage at a higher or lower level of pitch”. (The Oxford Dictionary of Music, Kennedy, M.).

I am going to explain sequences in music by showing/playing you various examples.
Have a look/listen to the following example of a sequence:

Music Theory Sequence Example

      Play Sequence Example

This is a clear example of a sequence.
You can see how the short melodic phrase is played and then repeated at a higher level of pitch.
The same pattern is then repeated again at a higher pitch, etc..

Types of Sequences

There are 2 main types of sequence you will come across in music:

  1. Melodic Sequence – This is the repetition of a melody (like in the above example)
  2. Harmonic Sequence – This is a repetition of a series of chords (I will explain this later)

When the word “sequence” is used it generally implies that both melodic and harmonic material is being used.

Examples of Melodic Sequences

Tonal sequence

In a tonal sequence the intervals between the notes are altered to some extent.
The interval size usually stays the same (i.e. 4th, 5th, etc..).
However, the interval quality changes (e.g. a minor interval may become a major interval) This change in quality is inevitable if the composer wants the key to remain unchanged.

In our example of a sequence you can see that the interval sizes remain the same across the 2 melodies (3rd, 3rd, 2nd, 2nd in the 1st melody stay as 3rd, 3rd, 2nd, 2nd in the repeated melody):
Tonal Melodic Sequence basic analysis
However, the interval qualities change (major 3rd, minor 3rd, major 2nd, minor 2nd in the first melody become minor 3rd, major 3rd, major 2nd, major 2nd in the repeated melody):
Tonal Sequence Example
These changes in quality continue through all 4 bars of the sequence and so our sequence example is a Tonal Sequence.

Real Sequence

In a real sequence there is no change in either the size or quality of the intervals (this will usually mean that the composer has to change the key as the sequence progresses).

If we convert our example of a sequence into a real sequence it would look as follows:
Real Sequence Example
You can see how we have converted the 2 “F” notes to “F sharp” notes so that the interval qualities remain the same.
The full sequence would look and sound like this:
Real Sequence full example

      Play Real Sequence Example

Can you hear how the music sounds like it is changing key (modulating) as the sequence progresses?

Mixed Sequence

A sequence that has several repetitions, some of which are tonal and some of which are real is called a Mixed Sequence.

Mixed Sequence Example

      Mixed Sequence Example

In the example above you can see that the sequence between the 1st two bars is a real sequence, whilst the remaining bars are tonal sequences.

Examples of Harmonic Sequences

Descending Harmonic Sequences

Descending Circle-of-Fifths Sequence

This sequence gets its name from the fact that each successive chord has a root note that is a fifth lower than the previous chord.

Descending Circle of Fifths Harmonic Sequence

      Descending circle of 5ths Harmonic Sequence

Descending Thirds Sequence

In a descending thirds sequence the chords move down a third for each repetition, hence the name.

Descending 3rds Harmonic Sequence Sheet Music

      Descending Thirds Harmonic Sequence

Ascending Harmonic Sequences

Ascending Circle-of-Fifths Sequence

In an ascending circle-of-fifths sequence each chord’s root is a 5th higher than the previous chord in the sequence.

Ascending circle of fifths Harmonic Sequence Sheet Music

      Ascending Circle of Fifths Harmonic Sequence

Composing Using Sequences

Sequences are an excellent tool for composing music – I use them in a lot of the pieces I write.

Have a look/listen to this piano piece I wrote called “A Time To Mourn”.
The piece shows clear examples of melodic and harmonic sequences (I have annotated the sheet music to show the sequences).
A Time To Mourn piano sheet music with annotated sequences

      A Time To Mourn by Ben Dunnett

You will find lots of examples of sequences in the music you listen to.
A famous example of a descending melodic sequence can be found in the well known Christmas carol “Ding Dong Merrily on High”.
Have a look/listen to this example below:
Ding Dong Merrily on High descending tonal melodic sequence example
      Ding Dong Merrily on High

I hope you have found this lesson on sequences helpful.
My advice would be to try composing/improvising some short melodies and then experiment with repeating them at different transpositions.
I am sure that you will be pleasantly surprised by what you discover!

As always, if you have any questions, please feel free to contact me.