Bortniansky returned to the Saint Petersburg Court Capella in 1779 and flourished creatively. He composed at least four more operas (all in French, with libretti by Franz-Hermann Lafermière): "Le Faucon" (1786), "La fête du seigneur" (1786), "Don Carlos" (1786), and "Le fils-rival ou La moderne Stratonice" (1787). Bortniansky wrote a number of instrumental works at this time, including piano sonatas and a piano quintet with harp, and a cycle of French songs. He also composed liturgical music for the Orthodox Church, combining the Eastern and Western European styles of sacred music, incorporating the polyphony he learned in Italy; some works were polychoral, using a style descended from the Venetian polychoral technique of the Gabrielis.