The St. Nicholas parish church in Elbląg, currently the Elbląg diocese cathedral, is a unique building in every respect. Until today, it remains the most important element of the town and reflects its turbulent history. Since its erection, the church was an important centre of liturgical music. The paper discusses the changes in the organ instruments of the largest Elbląg church after the fire of 26 April 1777 until 1945. Their story has remained largely unknown until today. It is particularly surprising that no one analysed the issue of the instrument’s history in St. Nicholas’ church ever since it became a cathedral. The author of this paper intends to contribute to reviewing the history of the grand renovation of the church of St. Nicholas after the fire of 1777.