The choir performed works by Vivaldi and Handel under the baton of Magnus Kjjelson.
Until October 1, the event, held under the auspices of President Kolinda Grabar-Kitarovic, will feature another 27 concerts in Varazdin, several other locations in Croatia and in Ptuj, Slovenia.
This is the first time the partner country is Scandinavian.
"Swedes love music, Sweden has the largest number of choirs in the world per capita, and since the group ABBA, we have been the third largest exporter of music in the world," Ambassador Diana Helen Madunic said at the opening ceremony.
The festival includes performances by several Swedish musicians such as the Renaissance ensemble Romeo & Julia Kören, the Hazelius Hedin folk duo, organist Hans Fagius, Ensemble Villancico and the Royal Swedish Chamber Orchestra, the Oslo Circles baroque ensemble from Norway as well as Croatia's Project Lazarus, Responsorium, Antiphonus and the Croatian Baroque Ensemble.
The festival also brings accompanying events under the title Total Baroque which include an international flower show, a photo and sculpture exhibition by Stephan Lupino, and a gastronomy offer including baroque beer and wine.