In 1862 he met Brahms, who became a lifelong friend; Brahms cared for Nottebohm in his last illness and took care of the arrangements for his funeral.
Through Herzogenberg she also met Clara Schumann and Brahms.
(Schumann was not at home, and would not meet Brahms until the next day.)
In Leipzig, he and his parents were part of the musical circle around Heinrich von Herzogenberg, and it was at their house that he first met Brahms.
In 1853 he met Brahms.
He met Brahms in the 1860s, when the composer was a rising star of the Viennese musical scene.
He went to Bonn for the Schumann Festival held there, where he met Joachim and Brahms.
During Lenneth's travels, she meets Brahms, lord of the undead and enemy of Odin, who possesses her sister Silmeria (due to circumstances explained in Valkyrie Profile 2: Silmeria) and the necromancer Lezard Valeth, who lures her to his tower.
From 1851 he studied composition with Robert Schumann in Düsseldorf, where in October 1853 he first met Brahms and collaborated with Schumann and Brahms on the 'F-A-E' Sonata for Joseph Joachim (Dietrich composed the substantial first movement).
Although Stanford had met Brahms, it was quite likely that Mühlfeld wasn't keen to play the concerto because of its derivative aspects - there is still that unique Irish/Gallic quality in so much of the writing.