By the mid-19th century, the burgeoning piano industry was in full flower, incorporating many developments and improvements in design. This led to increased consumer demand and mass production. Consequently the piano evolved from being a luxury item to home entertainment center. Until the advent of radio and recordings, this was how you experienced music at home. Apart from traveling to concerts, the only way to get to know, say, a new Brahms Symphony or the latest Wagner or Verdi opera was to play them at the piano, more often than not in arrangements for one piano four hands.

Glancing through myriad music catalogs (not to mention IMSLP), it seems that nearly every symphony, string quartet, choral work and opera had once been available in duet arrangements. Most publishers employed staff arrangers for this task; indeed, one could find certain works in more than one or two editions, such as the Beethoven Symphonies. Composers like Liszt, Brahms, Smetana and Dvorak either made their own four hand arrangements or else supervised others to do so. In essence, the piano duet medium represented the most viable way to dissemenate new orchestral works, particularly those for which concert performances were few and far between. One case in point concerns Bruckner’s 1877 reworking of his Symphony No. 3. Although it had little success, that didn’t stop the 18-year-old Gustav Mahler from transcribing it for piano duet for what is considered to be Mahler’s first publication. In turn, Mahler’s disciple Bruno Walter arranged Mahler’s First and Second Symphonies for four hands. And Alexander von Zemlinsky, another close member of Mahler’s inner circle, unveiled his four-hand version of the Sixth in 1906.