Flentrop was responsible for more than 250 new instruments, and over 100 restorations, typically showing unusual respect for existing material. Between 1953 and 1955 Flentrop undertook a major reconstruction on the 1721 Schnitger organ of the "Grote of St. Michaelskerk" in
Zwolle, Netherlands in an effort to restore the organ to its original quality. He returned to this task later, with new information about restoration of classical organs, making a series of adjustments over a period of two decades. Flentrop had an important influence on American organ building in the classical style. Flentrop designed the 5,000-pipe organ in the Duke University chapel, based on a classically designed 18th century organ. The organ was built in the Netherlands of solid wood, using electricity only to power the blower, and was played there before being dismantled and shipped to the United States. It was first officially played there on Christmas Day, 1976. His company built the pipe organ in Messiah Lutheran Church in
Germantown, Maryland, dedicated on 21 April 1991. The organ is encased in French Oak, with cedar and mahogany used for some of the interior mechanical parts. The organ uses electricity only to supply air, with the keyboards mechanically connected to the pipes. Apart from its excellent acoustical qualities, the instrument is a fine example of woodworking and cabinet making. ==Bibliography==