What are Sequences in Music?
A sequence is where a passage of music is repeated at a higher or lower level of pitch.
The repeat can be an exact transposition – a real sequence or the intervals can be changed – a tonal sequence.
The Oxford Dictionary of Music defines a sequence as the “more or less exact repetition of a passage at a higher or lower level of pitch”. (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:
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:
- Melodic Sequence – This is the repetition of a melody (like in the above example)
- 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.
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):
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):
These changes in quality continue through all 4 bars of the sequence and so our sequence example is a Tonal 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:
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:
Can you hear how the music sounds like it is changing key (modulating) as the sequence progresses?
A sequence that has several repetitions, some of which are tonal and some of which are real is called a Mixed Sequence.
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.
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 Thirds Sequence
In a descending thirds sequence the chords move down a third for each repetition, hence the name.
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.
Composing Using Sequences
Sequences are an excellent tool for composing music – I use them in a lot of the pieces I write.
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:
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.