The great German surgeon Theodor Billroth and the imaginative and creative composer Johannes Brahms had a very close friendship centered on musical activities, that lasted for more than thirty years while they lived and worked in Zurich and Vienna, during the second half of the Nineteenth Century. Billroth, besides his all-consuming medical activities, had time to be a musical enthusiast who directed orchestras, played the violin in chamber music groups, and wrote musical criticism for newspapers. The common affection between these two creative giants is documented by their abundant and effusive correspondence, by the constant requests by Brahms of Billroth’s opinions regarding his compositions, and by the positive and stimulating answers that Billroth gave to these requests. Billroth opened his house for musical evenings to play Brahms chamber compositions for the first time, and Brahms dedicated his two Opus 51 string quartets Nos. 1 and 2, known in the musical milieu as Billroth I and II, to his physician friend. Unfortunately, the close bonds between these two geniuses weakened towards the end of their lives as a result of Billroth’s becoming intolerant to the lack of social refinements and gruff behavior of the composer. This baffling intolerance of Billroth to his friend Brahms can be better understood after reading Billroth’s writings in his book The Medical Sciences in the German Universities. A Study in the History of Civilization. There Billroth expresses strong prejudices against potential medical students of humble social origins, such as those of Brahms, coupled to a primitive anti-Semitism.