section_path: History/Instrumental technology
section_name: Instrumental technology
paragraph_text: Instrumental technology
  
  The invention of the piston and rotary valve by Heinrich Stölzel and Friedrich Blühmel, both Silesians, in 1815, was the first in a series of innovations which impacted the orchestra, including the development of modern keywork for the flute by Theobald Boehm and the innovations of Adolphe Sax in the woodwinds, notably the invention of the saxophone. These advances would lead Hector Berlioz to write a landmark book on instrumentation, which were the first systematic treatise on using instrumental sound as an expressive element of music.