The world-famous composer Edvard Grieg is one of the most internationally renowned Norwegians. The letters from Grieg are written during one of his stays in Copenhagen to an employee at Hornung & Møller, which was the leading piano manufacturer at the time. They give an insight into Grieg's busy life as a famous composer, as well as his high standards and expectations to the instruments, he surrounded himself with: “August Winding og undertegnede vilde være Dem meget forbunden, om vi måtte få øve et Stykke for 2 Pianoer et eller andet Sted i Deres Lokaler, og siger Winding, ikke i den tomme Koncertsal, hvor Ræsonnansen umuligjør Studiet” (“August Winding and I would be bound to you, if we were allowed to rehearse a piece for 2 pianos somewhere within your facilities, and, says Winding, not in the empty concert hall, where the resonance makes practicing impossible”). In another letter, he writes: “Vil De være så venlig snarest gjørligt at sende en Stemmer op til mig. [...] Klaveret har med Et fuldstændig skabt sig galt”. (“Will you please as soon as possible send a tuner up to see me. [...] The piano is all of a sudden acting up completely”.)

As the leading piano manufacturer within the Nordic countries, the Danish company Hornung & Møller (1827–1972) produced more than 50,000 instruments. From when the factory started production in the mid-1800's and well into the 20th century, Hornung & Møller built instruments of high quality, which are to be found in many Danish homes and cultural institutions today. The 70+ letters and letter cards sent to the piano factory also reveal names such as Edvard Brandes, Gustav Wied, C. Jacobsen, Carl Locher, Alexander Kielland, Joakim Skovgaard, Johanne Louise Heiberg, Michael Ancher and Edmund Neupert.