For Chydenius, music was his most cherished art form. At the beginning of the 1770’s he gathered together an orchestra of young musicians, which held paying concerts in the reception hall of the rectory. Public concerts of this type were held at that time in Finland elsewhere only in Turku. Chydenius’ collection of musical manuscripts has survived, and indicates that in Kokkola they followed the latest Continental fashions in music. The curate of the parish, Johan Snellman was also the agent for the Hummel firm of Dutch music publishers – the first in Finland.
The most famous piece in the library of manuscripts is Giovanni Battista Pergolesi‘s Stabat Mater. Possibly this piece was performed by the girls for whom Chydenius tells us he held choir rehearsals. Amongst the other composers were the Germans Franz Xavier Richter, Franz Anton Rosetti, Karl Friedrich Abel, and the Italians Luigi Boccherini, Gaëtano Pugnani and Antonio Sacchini. In 1790 Chydenius sold his library of manuscripts to the new musical society of Turku.