"Christian Albert Theodor Billroth (26 April 1829 – 6 February 1894) was an Austrian surgeon and amateur musician.
As a surgeon, he is generally regarded as the founding father of modern abdominal surgery. As a musician, he was a close friend and confidant of Johannes Brahms, a leading patron of the Viennese musical scene, and one of the first to attempt a scientific analysis of musicality." - (en.wikipedia.org 08.12.2020)
