A nice note from the Prussian-British pianist and conductor to the violinist Joseph Joachim: Because tonight I shall certainly forget, I want to remind you now that you have promised to provide a copy of the Sonata by Kahn. Please don't forget it; I should like to have it as soon as possible, also with other pieces by the same composer if there are any. Always yours…

Hallé is referring to the then twenty-year-old German composer Robert Kahn, who was an associate of both Brahms in Vienna and Joachim in Berlin. Joachim refers to the first of Kahn's four violin sonatas, which was completed earlier in the same year. Joachim's inquiry later resulted in the composition of a String Quartet, Op. 8, that was dedicated to the Joachim Quartet.

Hallé played the organ and percussion as a boy in Prussia. He then moved to Paris, where he often associated with Luigi Cherubini, Frédéric Chopin, and Franz Liszt, but chose to leave for England during the 1848 revolution. It was in England that he would really make his mark: he was the first pianist to play the complete series of Beethoven piano sonatas in that country, he founded the Hallé Orchestra and helped to found the Royal Manchester College of Music. Also, he invented a mechanical page-turner for pianists.