Whenever Gustav Mahler spoke of Beethoven, he did so with an air of reverence: “Among poets and composers of more recent times we can, perhaps, name but three: Shakespeare, Beethoven and Wagner.” Even so, Mahler the conductor considered Beethoven’s scores primarily as a challenge, as material that needed to be adapted for the orchestras and concert halls of his time. Richard Wagner had already studied Beethoven’s scores intensively and written about them in great detail. The balance in sound of the classical orchestra had developed, and a return to previous proportions was out of the question, given the increased size of the concert halls. People knew of the existence of Mahler's adaptations, but it was not until 1927 that Erwin Stein, the composer, pianist and music journalist active in Schoenberg’s circles, was able to report that all of Mahler’s conducting scores, replete with his “Retuschen” (retouchings), had in fact survived.