W. Sauer Orgelbau Frankfurt (Oder) is a German organ building workshop founded in 1857 by Wilhelm Sauer. In 1917, it came under the ownership of Walcker from Ludwigsburg, but retained its independence under its workshop manager Karl Ruther, including its name. It was one of the largest organ builders in Germany in the 19th and first half of the 20th centuries. After German reunification, in 1996, it was transformed into a GmbH with its headquarters and workshop in Müllrose (Brandenburg), and in 2000, a new founding took place. The company exists to this day.

The company developed into the leading organ builder in Prussia in the second half of the 19th century. Wilhelm Sauer retired in 1910 and sold his business to Paul Walcker, who had been the workshop manager since 1892 and deputy managing director since 1894. His nephew Oscar Walcker (1869–1948) from Ludwigsburg took over the company in 1917, which thereafter operated under the name "Wilhelm Sauer (Owner: Oscar Walcker)." Before World War II, between 100 and 120 employees were employed. Towards the end of the war, which had largely destroyed the workshops, they were plundered and used as a delousing facility. Anton Spallek embarked on a new beginning. By the end of 1945, six employees were working, and by the 1960s, there were around 30 employees. Gerhard Spallek, Anton Spallek's son, who had joined his father's workshop as an apprentice in 1945 and passed the master craftsman examination as an organ builder in 1962, took over the management in 1966.

In 1972, nationalization followed as "VEB Frankfurter Orgelbau Sauer," with 40 employees, and Gerhard Spallek became the factory director. On September 7, 1990, reprivatization took place as "W. Sauer Orgelbau (Owner: Werner Walcker-Mayer)." Gerhard Spallek served as managing director. In 1994, new workshops were established in Müllrose. From 1996, the company operated under "W. Sauer Orgelbau (Frankfurt/Oder) Dr. Walcker-Mayer GmbH & Co. KG." With the insolvency of the Walcker parent company in Kleinblittersdorf in 1999, Werner Walcker-Mayer withdrew as owner and managing director of W. Sauer Orgelbau. The profitable Müllrose company was to be included in the bankruptcy estate. The insolvency administrator awarded the contract for the new founding of the company, which operated profitably and was registered in the commercial register in June of the same year, to four committed men who contributed significant equity and took risks. Since January 27, 2000, it has operated under the name "W. Sauer Orgelbau Frankfurt (Oder) GmbH" and has been managed by these four shareholders ever since.

Wilhelm Sauer created organs in the late Romantic style and used cone chests. Instruments were produced in large numbers, but solid materials were usually valued. By 1910, 1,100 organs had been built. Sauer alone built 70 organs in Berlin. Under Paul Walcker, who switched to the slider chest, 90 organs were built in seven years. The number of new organ constructions under Oscar Walcker increased to about 1,600 by the time of World War II. Prior to nationalization, the company largely returned to the production of mechanical slider chests. After 1972, exports to Eastern European countries increased significantly. Opus 2276 was completed in 2011.

https://www.sauerorgelbau.de/
https://de.wikipedia.org/wiki/W._Sauer_Orgelbau_Frankfurt_(Oder)