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A replica with an unusual history


THE STORY STARTED IN 2004 with the discovery of an original Viennese fortepiano signed and dated February 2, 1802. The inscription, which was uncovered at the beginning of the restoration process, changed the course of events.

As it appeared, this instrument was in fact made in 1802 when Nannette Streicher (born Stein) was associated with her brother Matthäus Andreas Stein. This fortepiano has a keyboard compass of five-and-a-half octaves (FF to c4). It is the earliest still existing fortepiano from the builders FRERE et SOEUR STEIN which exceeds the keyboard compass of the Viennese fortepianos from that period.

The original instrument was restored by SIETSE KOK over a period of three years, during a unique process involving research and, simultaneously, the building of an exact replica which allowed to confirm a number of theoretical bases essential to the restoration. The associated research led to the publication of several articles on the topics of keyboard compass and the relation of the Stein/Streicher family to Beethoven in early 1800.

The 1802 original fortepiano and its replica are being played in concerts throughout Europe.

THE FRERE et SOEUR STEIN REPLICAS WHICH ARE CURRENTLY BEING BUILT BY SIETSE KOK are a direct result of this project. They are available in the ranges five-and-a-half as well as six octaves, and carry the nameplate D’après Frère et Soeur Stein d’Augsbourg à Vienne.


Inscription in the original instrument © Sietse Kok

d'après Frère et Soeur Stein d'Augsbourg à Vienne


Frère et Soeur Stein d’Augsbourg à Vienne is the signature of the Viennese piano builders Geschwister Stein, led by Nannette and Matthäus Andreas Stein. They are children of the famous instrument maker Johannes Andreas Stein of Augsburg, a specialist of the organ and designer of several combination instruments. Johann Stein started making fortepianos around 1750 and the development of the Prellzungen mechanic is attributed to him.

Nannette Stein was trained in her father’s Augsburg workshop from an early age. She established herself in Vienna in 1794 with her brother, and  in 1803 under the name Nannette Streicher, founding a piano firm which she led successfully with her husband Andreas Streicher. In 1812 they created a concert venue which became a center for musical life in Vienna.

The Frère et Soeur Stein fortepianos carry the strong heritage of the Stein family and are built in the tradition of excellence for which Johann Stein was already well-known. At the end of the 18th century in Vienna, the Stein siblings were considered to be among the best and finest keyboard instrument makers, combining outstanding craftsmanship and musicality. The Stein-Streicher family stood at the forefront of the development of the Viennese fortepiano in the early 1800s.

More on the Geschwister Stein in Vienna? Read news and research articles on the Stein 1802 Project website.

D'après Frère et Soeur Stein, five and half octaves / Sietse Kok.



SIETSE KOK(1970) is a graduate of the University of Groningen in the Netherlands, where he studied philosophy. His love for musical instruments began early, and as a young student, he started as an apprentice with the organ builder Bakker and Timmenga in Leeuwarden.

He traveled through Africa in search of old church organs before settling down in the town of Haarlem, the Netherlands. He worked on late nineteenth century and modern pianos at Andriessen Pianos and subsequently specialized in the restoration of keyboard instruments from before 1850. Since 2005 he has dedicated himself to the fortepianos of the Stein/ Streicher family. Sietse Kok builds exclusively replicas D’après Frère et Soeur Stein.

Sietse currently lives in the Charente Maritime region of France, between the Atlantic coast and the vineyards of the Cognac.

Planning a trip to the area? Visit Belleroq

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You may call or write for more information on these instruments. Would you like to to receive a price indication? Let me know. Contact me by any of the channels below.

Sietse Kok
Aumagne – FRANCE

 +31 6 14 53 03 33

Stein fortepiano replica | Instruments by SK