Johann Paul Geycke (1726-1804) was a prominent organ builder in 18th-century Hamburg. He established and ran his own workshop in the city, where he trained Georg Wilhelm Wilhelmy (1748-1806), who later became a noted organ builder himself. From 1765, Geycke successfully outcompeted Johann Daniel Busch (1735-1787) from Itzehoe, securing his position as a leading organ builder in Hamburg.

Geycke's legacy continued through his family. His son, Joachim Wilhelm Geycke (1768-1840), took over the workshop, maintaining the family's influence in the craft. Additionally, his grandson, Christian Heinrich Wolfsteller (1830-1897), and his son-in-law, Balthasar Wohlien (1745-1804) from the renowned Altona organ-building family Wohlien, further extended the family's contributions to the field of organ building.

https://de.wikipedia.org/wiki/Johann_Paul_Geycke