Hærpfer & Erman, originally founded as Dalstein-Hærpfer in 1863, was a prominent French organ-building company based in Boulay, Lorraine. The company was established by Johann Karl Härpfer, who had extensive experience with renowned organ builders such as Steinmeyer, Walcker, and Friedrich Haas. He partnered with Nicolas-Etienne Dalstein, a skilled carpenter who had worked with the famous French organ builder Cavaillé-Coll. Together, they combined their expertise to create high-quality organs, initially focusing on the local region but eventually expanding their influence across Lorraine, the Saarland, and the Palatinate.

The company was notable for its innovative use of the Kegellade (cone valve chest) as early as 1865 and later for integrating pneumatic and electric action into their instruments. Over time, the company underwent several leadership changes, with Fritz Hærpfer and Paul Dalstein introducing a sound ideal aligned with the Orgelbewegung (Organ Reform Movement) in the early 20th century. After World War II, the firm rebranded as Hærpfer & Erman and expanded its operations significantly, producing over 250 organs between 1948 and 1967. In 1979, Théo Hærpfer took over the company, emphasizing a return to traditional mechanical action before the company was ultimately dissolved following his death in 1998.

https://de.wikipedia.org/wiki/Haerpfer_%26_Erman