Simrock published almost all of Brahms's pieces from Opus 16 to Opus 120 and was very good friends with Brahms, even going on vacations to Italy with him. Because of Brahms, Simrock took a chance with the young Antonín Dvořák. Simrock generally paid Brahms well for his music, but with Dvořák he was often unwilling to publish orchestral pieces. Simrock was so involved in the lives of prominent musicians that Joseph Joachim came to believe that his wife Amalie was cheating on him with Simrock, and Brahms wrote a famous "lengthy letter" in support of Amalie's innocence, which "was cited in evidence at the [Joachims'] divorce proceedings."
^David Brodbeck, Brahms: Symphony No. 1 New York: Cambridge University Press (1997): 28. "In his next letter, dated 25 April , Simrock readily agreed to Brahms's request for the princely sum of 5000 Talers (15,000 [Deutsche] Marks)."
^Dvořák Cello Concerto By Jan Smaczny, page 11 Cambridge University Press, 1999
^Robert Anderson, "Brahms in Brief" The Musical Times Summer (1998): 69