Last unit, we learned different ways to transform motives in order to balance cohesion and musical themes with melodic interest and variety. Another way to extend and develop motives is through melodic sequencing.
First of all, what is a sequence? Sequences in music are a compositional technique that involves the repetition of a specific pattern of notes, typically at a different pitch level, with the same rhythm and interval structure.
There are two main types of sequences: ascending and descending. An ascending sequence is a repeated pattern of notes that moves upward in pitch level, typically by a stepwise motion. This creates a sense of forward motion and can be used to generate new harmonic and melodic possibilities. A descending sequence, on the other hand, is a repeated pattern of notes that moves downward in pitch level. Descending sequences often move down by fifths or thirds, but they also can move down by steps.
Melodic sequences occur when a musical idea is expressed, then repeated one or more times, usually at different pitch levels. Here is an example:
Image via Music Theory Academy
There are two important vocabulary words to know when talking about melodic sequences: the pattern and the level of transposition.
First, the pattern is the original musical idea that was expressed and is being repeated. Sometimes, a pattern can be a motive, but it doesn’t always have to be. Usually, a motive is a thematic musical idea that is transformed and developed throughout a piece of music, or throughout a large section of that piece. For example, a motive might just be present during the B section of a piece in sonata format (which usually consists of contrasting A and B sections, called the exposition and development respectively, and ends with a recapitulation of the A section).
A pattern, on the other hand, might just be repeated a few times in a melodic sequence, and never appear again in the piece. It is also important to note that in this context, a pattern is usually defined both by its melodic and rhythmic properties, and these properties are usually retained throughout a melodic sequence. You might add some ornaments or decorations to the pattern, but you won’t transform it dramatically when writing a melodic sequencing. Motives, on the other hand, will be transformed and developed extensively throughout a piece. A pattern could be a specific instance of a motive that is repeated several times in a sequence.
Second, the level of transposition is the interval by which you are ascending or descending for each iteration of the melodic sequence. It is usually appropriate for the level of transposition in a melodic sequence to be either steps or thirds. We don’t want to have big intervals between instances of the melody.
Melodic sequences can be diatonic or chromatic. Diatonic melodic sequences stay in the key that they were written in. This implies that the quality of the interval might change depending on the starting note of the scale. For example, if you are in F minor and descending stepwise starting on F, you might first descend by a Major 2nd to start on Eb, and then you will descend by another Major 2nd to start on Db, but eventually, but then you will descend by a minor second to start on C natural.
Chromatic melodic sequences, on the other hand, use accidentals to keep the interval quality exactly the same between iterations of the melodic pattern. Usually, when writing chromatic melodic sequences, the composer will often keep interval qualities between successive notes in the melodic pattern the same as well – essentially writing the exact same melody in a different key. Chromatic melodic sequences are often used when modulating to a new key.
Here is an example of a chromatic melodic sequence:
Image via MyMusicTheory
Usually, the size of the level of transposition stays consistent throughout the sequence, although its quality might change based on the diatonic scale. We are also usually consistent with the direction of the melodic sequence. It is usually either ascending or descending – the melody doesn’t move erratically up and down (that would sound strange!).
There is one exception to this convention: when you are moving through the tones of a chord. For example, if a melody starts on a G, then you can ascend it by a fourth to have it start on C, and then ascend it by a third to have it start on an E, to complete an arpeggiation of a C Major chord. Similarly, if a melody starts on a C, you might transpose it up by a third to have it start on an E, then move it back down to start on a C, and then move it down by a third to have it start on an A, thus completing the tones of an A minor triad.
Melodic sequences have two primary functions in music: prolonging the tonic area and signaling motion to another key.
When using melodic sequences to prolong the tonic area, which is the musical key or center of the piece, composers proceed by repeating a specific pattern of notes that are primarily found in the tonic key. For example, if we are in Ab Major, we might write an ascending melodic sequence by thirds, starting on Ab, then on C, and then on Eb. This creates a sense of stability and repose in the music and can help to establish the tonic key as the center of the piece.
Additionally, composers can use inversion sequences where the sequence is played with the intervals in reverse order, this maintains the tonic area as the center of the piece. This can also be used to create a sense of development and continuity while also reinforcing the tonic key.
Most of the time, these melodic sequences will be diatonic, meaning that they won’t incorporate accidentals, since these accidentals will detract from the stability of the tonic area.
Melodic sequences can also be used to modulate, or transition, to a different key. Modulation is the process of moving from one key to another in a piece of music, and it can be used to create a sense of tension and release or to add interest and variety to the music. Because melodic sequences imply a sense of forward motion within a melody, using them to modulate is good way to transition to a new key.
One way to use melodic sequences to modulate to a different key is to start with a sequence in the tonic key and gradually introduce notes from the target key. This can create a sense of tension and release as the listener anticipates the modulation. Once the target key is established, the sequence can be repeated in the new key, creating a sense of continuity and stability.
These melodic sequences are usually chromatic: the composer might ascend or descend by steps or thirds until they reach their target key. They also might move up or down the circle of fifths, following common harmonic progressions that signal modulation to a different key.
🦜 Polly wants a progress tracker: Beethoven uses melodic sequences several times in the third movement of his Sonata No 17 in d minor
. Can you find all of the melodic sequences? Which ones are diatonic and which ones are chromatic? Which ones are used for tonic prolongation and which ones are used to signal motion to another key?
There are many examples of melodic sequences in classical music. Here are a few examples from well-known pieces:
The theme from Beethoven's Fifth Symphony - The famous four-note motif that opens the piece is a simple ascending sequence that is repeated and developed throughout the symphony.
Mozart's Symphony No. 40 in G minor, K. 550 - In the first movement, Mozart uses a descending melodic sequence in the violins that is repeated and developed throughout the movement.
Tchaikovsky's Symphony No. 5 in E minor, Op. 64 - The main theme of the first movement is a descending melodic sequence that is repeated and developed throughout the movement, creating a sense of continuity and stability.
Chopin's Prelude No. 15 in D flat major - Chopin uses a descending melodic sequence in the left hand that is repeated and developed throughout the piece, creating a sense of continuity and stability.
Bach's Prelude in C Major BWV 846 - This Prelude is a great example of a melodic sequence, it's a series of ascending arpeggios that are repeated and developed throughout the piece, creating a sense of continuity and stability.
There are also several examples of melodic sequences in popular music. Listen to them with your music theory headphones 🎧and see if you can hear them:
The chorus of “Radioactive” by Imagine Dragons
Briefly, in the pick-up to the chorus of “Heart Attack” by Demi Lovato
The bridge of “Teenage Dream” by Katy Perry
Justin Timberlake’s “Mirrors”
Pretty much any song by Billy Joel – notably, "Allentown," "Pressure," and "New York State of Mind.” Billy Joel in particular often uses a technique where he writes a melodic sequence, and then extends the pattern, and then writes another melodic sequence based on that pattern. This is another way to write interesting melodies and prolong phrases or sections of a melody.