Hermann Kröger, also known as Harmen Kröger, was a notable German organ builder based in Nienburg/Weser during the 17th century, with his work significantly influencing the Oldenburg organ landscape. Although details about his life are sparse, it is known that he worked in several regions, including Oldenburg, Minden, and Celle, before settling in Nienburg around 1655. Kröger was initially associated with the organ builder Cordt Kröger, possibly his relative, and completed Cordt's work on the Lambertikirche in Oldenburg after his death.

Kröger is particularly recognized for his advancements in the design and construction of Springladen (spring chests) and for building organs with independent pedal towers, a feature that added distinctiveness to his instruments. His craftsmanship included intricate knorpelstil carvings above the Brustwerk doors and the use of pure lead for metal pipes, often adorned with painted grotesque faces on the largest pipes. His legacy is also linked to his master apprentice, Berendt Hus, who later became the teacher of the famous Arp Schnitger. Kröger's work bridged the brabantisch-norddeutsche organ-building traditions of the Scherer and Fritzsche families, passing these techniques to Schnitger, thus influencing the course of North German organ building. His most complete surviving work is the organ in St. Laurentius, Langwarden.

https://de.wikipedia.org/wiki/Hermann_Kr%C3%B6ger