I recently made brief mention of a paper by the musicologist Michael Lorenz, in which he announced the discovery of a hitherto unknown godson of Mozart, named Wolfgang Amade Nebe. I asked Dr. Lorenz for more details, and here they are:
The discovery of Mozart as godfather resembles an unknown room that suddenly opens in Mozart's life. The godchild's father, Andreas Nebe (b. 1741 Hettstadt in Saxony, d. 1811 Vienna), was a servant of Count Karl Joseph von Palm-Gundelfingen (1749-1814), and he must have made Mozart's acquaintance in the Count's house. Palm was a great lover of music and also was one of the subscribers of Mozart's 1784 concerts in the Trattnerhof. The baptism took place on May 30, 1787, in the Piarist Church of Maria Treu, the parish church of the suburb Josephstadt (of Bruckner fame). Mozart could not be present, which was obviously caused by the fact that on this very day he received word of his father's death. Therefore he was substituted by the state official Johann Sattmann, a friend of Nebe or Mozart or both (see the picture above, the key passage in the baptismal entry reading: "anstatt und im Nam[en] des H[errn] Amadeus Wolfgang Mozart Kapellmeisters").... The only person [among the guests] who could be linked to Mozart was the midwife Sophia Stadler (1724-1790), the mother of the two legendary clarinet players Anton and Johann Stadler.
Wolfgang Amade Nebe attended the Piaristengymnasium (where he must have met Carl Mozart, who also attended this school) and in 1807 became an unpaid employee of the conscription office of the Vienna Magistrate (which was the office responsible for keeping track of the male populace that was liable to military service). In 1813 he was appointed a definite post at this office and took the oath as "Wiener Bürger" (Viennese Citizen). One year after the death of his mother, in 1836, Nebe married Anna Dander (1783-1865), the widow of a Tyrolian chestnut vendor.
Wolfgang Amade Nebe thought highly of himself, perhaps owing to his famous godfather. He occasionally pretended to have a social status that did not have, and his self-esteem sometimes bordered on fraud. In his marriage contract he described himself as "honorary citizen" of Vienna, a status he did not possess; his illiterate wife probably believed it and she certainly also believed him when he told her that his father had been a "doctor of medicine." But that's not all. On April 6, 1814, Nebe stood godfather to a daughter of a friend in the parish church of Alservorstadt and in the baptismal record he set the flamboyant (and pretentious) signature: "Wolfgangus Amade edl[er][!] V[on] Nebe." Wolfgang Amade Nebe died on June 11, 1839, at his home in Breitenfeld No. 15 (today Laudongasse 40), of abdominal dropsy. His widow, Anna Nebe, drew her widow's pension for 26 more years. She died at 82, of old age, on November 12, 1865.
How could Mozart's godfatherhood have remained undetected for so long? From my decade-long experience investigating the great composers of the Viennese classical era in the Viennese church records I draw the following conclusion: musicians (even if they had a permanent position) were not valued among professional colleagues as godparents. People preferred aristocrats, civil servants, artisans and citizens with a secure income. Of course, prominent musicians appear in the Vienna church books (particularly Antonio Salieri, who as "Hofkapellmeister" was an enthusiastic godfather and witness). But it is obvious that Mozart avoided familial responsibilities of this kind, and his absence as a godparent to the children of composers and musicians who were his friends seems to suggest reluctance. In this he evinces the same intentional reticence as Ludwig van Beethoven and Franz Schubert.
I admit to being curious about another paper appearing in the same issue of Acta Mozartiana that contains Dr. Lorenz's work—namely, Joachim Brügge's "'Mozart was crazy. Flat fucking crazy': Mozart am Broadway 2010."