Birgit Heise and her team have published a very interesting article in the DMM (Sep 2017) - Topic: The artist contracts of Hupfeld These documents are part of a very extensive collection of original Hupfeld documents in the Saxon State Archive, State Archive Leipzig.
More than 180 artists, including Grieg, Reisenauer, Reinecke, Leschetizky, von Sauer and many more, and their contracts are documented there - with details of prices, pieces of music, rights etc. It is still unclear why not all contract documents can be found here.
The cross-references to contracts with the "competitor" M. Welte & Söhne in Freiburg are also very interesting. As a rule, the artist was forbidden to record identical pieces with the competition. The references to "dynamic performance instructions" for the editorial process are also very valuable. The more popular the artist, the higher the remuneration and the greater his or her freedom in the contract text. In principle, just like today.
The contracts were generally bilateral standard contracts with individual adjustments. These received Hupfeld documents are currently the only documentation of this contractual basis between artist and company. Valuable personal comments are scattered in the diaries and letters of the individual artists. We are sure that very important discoveries will be made in the near future.