Historically, European opera houses have been the traditional training ground for young conductors of all kinds. Before prospective conductors were entrusted with leading performances, they began coaching singers on the piano, rehearsing the choir and supporting senior conductors. (This was the path of Dudamel’s predecessor in Paris, Philippe Jordan, 46, who moved to the Vienna State Opera.)
Working directly with singers was and is vital. When all instrumentalists imitate the human voice to a certain extent, opera conductors gain a special feel for the art of forming a long lyrical line: they learn to breathe with singers, to anticipate the melodic tempo and flow of fine singers . But you also have to lead these singers and almost curb them, so that their lines do not slack off with too much expression. This sensitivity develops with long practice. Opera also forces young conductors to hone their skills as musical traffic cops by coordinating singers and choristers (who are often far apart on stage) and the players in the box.
The traditional way of learning the conducting profession through the opera was illustrated by Gustav Mahler, who in his youth worked in opera houses in Prague, Leipzig and Hamburg and then became director of the Vienna State Opera and briefly chief conductor at the Met. During this time he was director also major orchestras, including the New York Philharmonic from 1909 until his death in 1911. Although he was known for his visionary symphonies and never wrote an opera, Mahler conducted most of his conducting in opera houses.
Toscanini spent the first half of his long career in opera, working tirelessly in Italian houses. By today’s standards, he would be considered a specialist in new music as he directed many premieres, including “La Bohème” in 1896, the year he conducted his first symphonic concert. In 1898 he became chief conductor of the Teatro alla Scala in Milan and in 1908 took the main position at the Met before returning to La Scala. Then, in 1928, he became music director of the New York Philharmonic and never ran an opera house again. In 1937, NBC formed for him the NBC Symphony, a high-profile orchestra, and his broadcasts gained a large following (including an influential series of opera performances).
George Szell is so well known for his long tenure as music director of the Cleveland Orchestra (1946-70) that it is sometimes forgotten that he spent much of his early professional life in the opera. This includes the Berlin State Opera, in which the young Szell was looked after by Richard Strauss; Szell eventually becomes chief conductor there. In the 1940s, Szell conducted regularly at the Met, including two celebrated “Ring” cycles. Then, in 1950, Rudolf Bing, who didn’t like Szell, took over the management of the company, and Szell made his last appearance there in 1954. Anyway, he was based in Cleveland until then and never looked back.