Heinrich David Stölzel (7 September 1777 – 16 February 1844) was a German horn player who developed some of the first valves for brass instruments.
His father was also a musician, and as a young man he learnt to play numerous instruments, including harp, violin, trumpet and horn.
[2] Stölzel reportedly wrote directly to King Friedrich Wilhelm III of Prussia to publicise his invention, and musical director Gottlob Benedikt Bierey of the Beslau City Theatre wrote in the Allgemeine musikalische Zeitung on 3 May 1815: "Heinrich Stölzel, the chamber musician from Pless in Upper Silesia, in order to perfect the Waldhorn, has succeeded in attaching a simple mechanism to the instrument, thanks to which he has obtained all the notes of the chromatic scale in a range of almost three octaves, with a good, strong and pure tone.
"[3][4] Fellow inventor and musician Friedrich Blühmel also designed a similar valve system independently of Stölzel around the same time.
Stölzel's early two-valve horn design was soon expanded to three by instrument builder Christian Friedrich Sattler of Leipzig, and the first valve trumpets were built in 1820.