Gottfried Christoph Härtel and Johann Anton André were two rival publishers who were looking to publish Mozart’s works. Concerning the requiem, it became particularly nasty.
Härtel’s first correspondence with Constanze took place on March 11, 1799. He had obtained two copies of the requiem, and not sure if they were reliable, decided to ask Constanze about it. Referring to the musical excerpt Härtel had mailed to her, Constanze said it was “approximately what Mozart had written, but not exactly.”
Constanze’s copy was not the autograph. Different people had received parts of the original, including the commissioner. She still had people believing she did, however. When she wrote to Härtel, she was trying to say that she had the autograph, and since hers was a little different from his, hers was more authentic. In reality, the copies were exactly the same. Constanze then mentioned a little about the completion of the work:
“Just how much of it was written by [Mozart] himself (almost everything, except the end) I shall explain to you when I give it to you, but this is what happened: When Mozart believed he was going to die, he talked to Herr Süssmayr, now Imperial-Royal Kapellmeister. Mozart told him that, if he really were to die before he finished it, the first fugue should be repeated at the end, which was customary anyway. He also instructed Süssmayr just how to complete the work, the main [vocal and instrumental] parts already having been indicated by Mozart. This is indeed what Herr Süssmayr then did.”
Härtel would not settle for scanty bits of information, and he claimed he had two copies and intended to use them. Constanze decided to act offended and brought up the topic of the anonymous patron. She claimed there was no one who could publish the requiem except for the patron (she did not mention Count Walsegg by name) or herself if he consented. She promised to work things out with the patron and requested fifty ducats for the rights to the requiem and for the information Härtel had asked for.
This was ten times the amount Härtel was prepared to pay, so he angrily told her that he would publish the requiem, with his own copy if not with hers. Constanze soon came around and offered her copy to him for 25 gulden and 10 copies of printed edition. This was not much of a bargain for her, and she knew it.
Constanze tried to make money off of the other unpublished Mozart works, since “no one holds any rights to these but I; no one has any right to publish them without my permission. There can be no question about that.” Then she took a vacation, so Georg Nikolaus von Nissen, with whom she was living, sent her copy to Härtel.
Constanze returned to find out that a rumor had started about her having circulated unauthorized copies. She panicked and asked Härtel not to announce publicly he had received a copy from her. Too late! Härtel already had, publishing an announcement saying “based on the manuscript furnished for this purpose by Mozart’s widow.” His announcement does not contain a word about Süssmayr and his completing the score.
Constanze told Härtel that the anonymous patron could not blame her when the printed edition came out, since even before she had gotten involved, Härtel had two copies and could publish them. She also said she would insert a declaration in the newspapers to appeal to the patron to allow publication.
Härtel knew he was to blame now, so he turned to Mozart’s sister Nannerl for help. She couldn’t deal with the problems concerning the requiem, since at the time Mozart began to write it the brother-sister relationship had collapsed.
Constanze could not afford to stand by idly, so she turned to Johann Anton André. Constanze offered to sell Mozart’s entire musical estate to Härtel for 4,050 gulden, but André was only willing to pay 2,550 gulden. She allowed André a period of two months in which she could cancel the agreement at any time. During the two months, she implored Härtel to accept the entire package she was offering. Härtel ignored her, forcing her to sell to André.
This was a terrible mistake. She had incurred the loss of 1500 gulden and André’s printing quality was not very good. Härtel should have been delighted at Constanze’s failure, but now he, too, was in an awkward situation. He had missed out on the complete edition, and his only hope was the requiem. But things were unclear concerning the requiem. How reliable was his copy? What was Süssmayr’s role?
Instead of negotiating further, Constanze handed things over to Süssmayr. Härtel contacted Süssmayr, who replied by return mail. Süssmayr was going to say something, finally—he had remained in the background during the whole incident, and aside from this one letter, he never made any more public statements concerning the requiem.