Baroque-era composer Johann Sebastian Bach is arguably the most influential composer in human history. These days, his music, more than any other composer's, is still being studied, analysed and performed – setting the stage for the constant evolution of classical music for centuries to come.

Bach’s innovations have had a direct influence on the music of Central Europe in the Classical period, but in the post-Beethovenian Romantic period, that influence has somewhat subsided (not neglected, however). That is, until the final decades of the 19th century, during which the composers at the time – most of whom have studied Bach’s music like their older contemporaries – began to implement musical elements inspired by his works into their modern compositions. This sudden surge of interest in Bach’s music was unprecedented, but its appeal to the late Romantic and Modern composers can be explained by understanding what musical realms he revolutionised, and by tracing his legacy through music history.

Continuing to refine his contrapuntal style for his whole life, Bach helped an important compositional technique gain attention…

Bach, unlike his contemporaries of the Baroque era, did express an interest in the Gregorian chants that had been music for the church for centuries until the Renaissance period, or more specifically, he was interested in the Cantus Firmus (“fixed song”). Shortly, a Cantus Firmus is a two-voice form in which one voice provides an active melody and the other provides sustained notes. This is, in fact, already polyphony (two or more voices that ‘sing’ different notes at the same time). By the Baroque era, there was much more complex music, and certainly more than two voices going on at the same time. Polyphony, as well as Harmony, have evolved massively since the Cantus Firmus. But while the Renaissance era did borrow from the Cantus form of Polyphony, the Baroque period composers sought to emancipate their music from it, writing pieces for many active voices. That is, until Bach, who wanted more clarity (or, less density) in music, which brought him back to the Cantus Firmus.

Now, we can talk about Counterpoint. “Punctus contra punctum”, Latin for “point against point”, is “… the relationship between voices that are harmonically interdependent, yet independent in rhythm and contour”. To put it simply, it is polyphonic activity on a time grid. Counterpoint, or Kontrapunkt in many languages, has naturally evolved with polyphony, and also with the establishing of the ‘measured music’ – a music that has a defined duration, dictated by the composer by means of aligning the notes in measures with precise note lengths, and with indication of metre (time signatures) and tempo. The collision between polyphony and ‘measured music’ happened in the early Renaissance, and by the Baroque era, most music was a result of this merge: Contrapuntal music.

Bach was not a fan of the density of Contrapuntal music in his time, and in his own works, aspired to have the main melody/melodies stand out. And how does one achieve that? By having less activity in the other voices surrounding it. It’s important to mention that in Bach’s time, instrumental music was already very common, so by becoming a masterful orchestrator, Bach was very successful at his task of conveying his melodies in his pieces, again, by utilising counterpoint to his advantage. Continuing to refine his contrapuntal style for his whole life, Bach helped an important compositional technique gain attention: the Fugue.

A fugue is a loose form, built on a musical subject which is imitated, often in different pitches, by other voices throughout the piece. Fugues usually have three sections: an exposition (introduction of the musical ideas in all of the voices), a development (mostly based on ideas presented in the exposition) and a return of the subject to the tonic key. When composers of the late 19th century and early 20th century started to incorporate some of Bach’s ideas into their own music, the Fugue was one of the most popular ideas to tackle. Composers of the Classical period, like Haydn and Mozart, continued writing in a contrapuntal fashion like that which had been established in Bach’s works. But with the modernisation some of the ideas had gone through at the hands of, amongst others, Bach’s own son Carl Philipp Emanuel, the Classical musical ‘dialect’ consisted of even less active voices operating simultaneously, and consequentially there was a larger focus on melodies which were at the front, and counter-melodies, which were less prominent.

Naturally, there were quite a few pieces which looked back at Bach’s contrapuntal works. Such one piece is Ludwig van Beethoven’s gargantuan Große Fuge (“Great Fugue”), for string quartet, a highly-criticized piece at the time it was published, during Beethoven’s late period. The reason behind the intense criticism it had received was the piece’s “complexity”, or, in other words, the lessened presence of the Classical “dialect”, of melodies and respective counter-melodies, which made it incomprehensible to Classical and early Romantic reviewers, musicologists and listeners. It is one of the last pieces of music to be written in a manner that is reminiscent of Bach’s contrapuntal style for 50 years.

Bach’s reputation as a composer increased during the Romantic period, thanks in part to the publishing and performances of his preserved works. Even so, the new music composed during that time had different goals: the gradually-expanding symphony orchestra and the further development of the instruments allowed more technical works to be composed, and that aligned with the grandeur the Romantic period had become associated with; pieces for larger ensembles in larger halls for greater audiences. It certainly wasn’t in a composer’s interest to alienate his audience, so while the subject matter for compositions had become more personal, the musical content was, for the most part, rather accessible. The melodies were at the front, evoking emotional and, often, nationalistic reactions. Felix Mendelssohn and German nationalism were instrumental in bringing Bach to the foreground, and paved the path for the revitalisation of the Bach-ian counterpoint in the works of Johannes Brahms. Inspired by the music produced in his own time, but also by folk music, the gallant music of the Classical period, and Bach’s music – Brahms seamlessly weaved complex contrapuntal ideas together while still operating within the Romantic mould.

that’s enough proof for the skeptics: Bach’s musical descendants, while not direct, are a good amount of the composers among us

Brahms was also known for rooting and assisting younger composers, probably because he himself was aided by Robert and Clara Schumann. Brahms had helped composers like Antonín Dvořák gain recognition, but he found particular interest in the music of a young Alexander von Zemlinsky.