Although Berlioz and Wagner began to incorporate ideas of what would become the modern conception of conducting, earlier composers such as Mozart and Beethoven contributed to this seminal field in their own individual ways.

Beethoven, for instance, used grand gestures and very public displays of emotion when he conducted, which showed up in later 19th-century practitioners such as von Bülow and in 20th-century conductors such as Bernstein. He provides a link, perhaps, between those conductors who were merely leading a group of musicians and those later ones who would tyrannize them.

But Beethoven was also considered a terrible conductor. Apart from his tragic deafness, which he refused to acknowledge when he conducted (causing him to miss the beats, among other things) he was famously truculent with musicians, thin-skinned, forgetful. Musicians were afraid of his outbursts (some refused to play under him) and often hoped he wouldn’t deign to conduct (though he insisted on conducting the premieres of his symphonies). As for his absent-mindedness, it showed up at the worst moments. There’s a story that at one point the great composer was playing a concerto and actually forgot that he was the soloist. He sprung up to conduct when he was supposed to be playing and threw his arms out to lead the musicians so dramatically that he knocked the lights off his piano.

Mozart, on the other hand, though exacting and sometimes testy with under-performing musicians, had the gift of empathy, and an ability to speak to musicians as fellow travelers (rather than to confront them as antagonists), knowing when to prod and when to tread lightly. He was perhaps a distant forerunner of such empathetic contemporary conductors as today’s young Gustavo Dudamel. And while Mozart generally conducted from the keyboard, there were instances when he would conduct while standing, using his hands to lead an ensemble, like conductors of later eras.

As the art of conducting evolved following the practices that Berlioz and Wagner introduced (both composers were, coincidentally, not only great conductors, but among the only conductors of any era who did not play either the piano or violin), which included extensive rehearsing, musicianship, an attention to the composer’s wishes (and keys), a sense of inner rhythm rather than marking time, the conductor’s role became an essential part of an orchestra’s sound, and his character before the public as the face of the orchestra would be one that most of us today would recognize.

During the course of the 19th century the conductor more and more became less of a composer-conductor, such as Mendelssohn, Wagner, Berlioz and Liszt, and a musician among musicians interpreting the work of composers (however idiosyncratically). Foremost among this new breed was Hans von Bülow, who had the outsized, caricature-ready conducting mannerisms of a Beethoven, the intractability of a Wagner, the ideals of a pure musician and the determination of a Hercules to shape orchestras to his will.

He was also in the Liszt-Wagner school of conducting that was primarily expressive rather than metronomic, that didn’t strictly hew to the beat, that allowed the rhythms of the music to speak, as it were. He had an impact on conductors such as Hans Richter, and on composer-conductor protégés such as Strauss and Brahms. His German-centric view of music also had an impact on American tastes in classical music (until the rise of Toscanini and others later).

And he had an influence on Gustav Mahler, conductor extraordinaire, composer of genius, and a man who combined the tyranny of Beethoven and von Bülow with the messianic fervor of Wagner and the hauteur of Berlioz.

More on Mahler next week. In the meantime, have a look on this site at a profile of the great conductor Nikolaus Harnoncourt.