Beethoven asks his colleague Karl Friedrich Zelter, head of the singing academy in Berlin, to intercede with the King of Prussia regarding a subscription for the Missa solemnis (op. 123). At the same time he mentions the possibility that the mass might - possibly in an a capella arrangement - also be useful for the singing academy's concerts.
Once the Missa solemnis was finished Beethoven sent 28 invitations to subscribe to the leading European courts, ten of whom sent a positive response. In order to encourage the princes to agree to do so, Beethoven simultaneously wrote to influential men he knew at the courts, hoping that they would intercede on his behalf. In the case of the Prussian king Beethoven not only wrote to Zelter, but also asked the king's Cabinet Secretary, Friedrich Duncker, and a further high-ranking Prussian official Prince Antoni Henryk Radziwill for support. Friedrich Wilhelm III of Prussia did actually order a copy of the mass; he was even the first subscriber from whom the composer heard.
