One of the most basic elements of musical composition is the sequence. As the word suggests, this is the sequential movement of a melodic line. The rhythm and intervals are maintained, but the line is repeated with different pitches. An obvious example is the opening two phrases of Mozart’s Rondo alla Turca.
Most composers have used sequences, at least to some extent. In jazz, they are a feature of Duke Ellington, Thelonious Monk and, more recently, Carla Bley. They can be heard informing the writing of Stravinsky and Shostakovich. It can be heard in much popular music, such as the second and third phrases in the Beatles’ Yesterday.
But as a broad generalisation, the use of sequences has declined since the advent of the Romantics in the 19th century, who tended to use them sparingly, if at all. It is this writer’s view that it has been a loss.
For this reason it is worth examining the use of sequences by the three acknowledged greats of the Western canon: Bach, Mozart and Beethoven. The key to using sequences well is both to surprise by setting up expectations, and then to satisfy with a sense of higher order, so that it is not surprise for surprise’s sake; mere novelty. Lesser composers are either overly predictable – Vivaldi’s sequences are overly easy to anticipate, for example – or they produce the unexpected, but it is aimless.
Baroque music was highly structured – sequences were typically the main means of organising the melodic line – so Bach’s use of sequences is at once obvious and filled with surprise and complexity. His sequences are often based on quite long lines that take the listener through a musical journey as he develops them through his extraordinary levels of harmonic invention, which have not been matched since.
Bach does not present the listener so much with melodic surprise as harmonic surprise, and the relative predictability of the sequences is the way that musical integrity is maintained. It is a demonstration of a truism about musical composition; that it needs to have a mix of the familiar and the original. Without the familiar, it does not connect. Without the original, it lapses into tedium.
Following Mozart’s use of sequence is the key to understanding his sublimity. He is the opposite of Bach; his surprises are more melodic than harmonic. He sets the listener up with obvious sequential development, but then moves the melody in ways that are anything but obvious.
Once again, there is a mix of the familiar: the obvious use of sequence; and the original: an unexpected development or resolution that takes the listener down surprising roads. Because Mozart was so supremely confident of his melodic prowess, the invitation to go on the melodic journey possesses an immediacy that has rarely been matched. It is a key to the intensely personal nature of his music, the sense that one is listening to a pure soul.
Beethoven’s use of sequence is different again. His sequences tend to be more collapsed, which gives his music much of its propelling force. Think, for example, of the famous four-note figure (da da da dum) in his Fifth Symphony. The movement starts off with the figure being used in an obvious sequence, but it is then inverted and turned into a driving series of rising lines. That approach is typical of Beethoven, who turned his short sequences into components of much longer lines that would rise or fall to produce growing intensity. Even when he did use very formal structures, such as the fugue in the 31st piano sonata, the figure that he develops contrapuntally is unusually short.
It is here, indeed, that the many Romantic-era imitators of Beethoven went wrong. They looked for the intensity, especially with their heavy orchestration and powerful polyphony. But they failed to emulate the use of sequence, which means that their music tends to sound less formed. Without underlying order, the music inclines to mere excess of sentiment rather than a penetration into the nature of things. The reason Beethoven’s ferocious pursuit of musical expression is so persuasive is that it also has underlying structure.
Sequence is not essential. Plenty of good music does not use it. But it is no coincidence that it was central to the art of the greatest composers.