This reference to Mozart in the diary of Count Karl von Zinzendorf is not in Dokumente, Addenda, or Neue Folge. It was discovered by Mary Sue Morrow, who includes the event in her 1989 book on Viennese concert life, although she does not transcribe Zinzendorf’s entry or name the performer (Morrow 1989, 374). The event took place the day after Zinzendorf’s well-known reference to the emperor speaking about the Mozart-Clementi duel, nearly a year after it had taken place (see our addendum for 5 Dec 1782, which sheds new light on that document).

The performer on 6 Dec 1782 was Baroness Ursula Margarethe Konstantia Louise Diede zum Fürstenstein, née von Callenberg, born in Muskau on 25 Aug 1752, the wife of Baron Wilhelm Christoph Diede zum Fürstenstein (1732–1807). Zinzendorf (and others) referred to her as “Louise.” Her older sister Countess Henriette Luise zur Lippe, née von Callenberg (1745–1799), was known as “Henriette”; she lived in Vienna with her husband Karl Christian zur Lippe-Weißenfeld, and appears often in Zinzendorf’s diaries. Zinzendorf was Louise and Henriette’s first cousin: their father, Reichsgraf Johann Alexander von Callenberg (1697–1776), was the brother of Zinzendorf’s mother, Countess Christiane Sophie von Zinzendorf und Pottendorf, née von Callenberg (1702–1775).

Both Henriette and Louise received excellent educations from tutors. According to an extended obituary of Louise published in 1805:

Sie sprach dahero, ausser der französischen Sprache auch die
englische, italienische, mit einer Fertigkeit und Eleganz, wie
Eingebohrne, und schrieb in diesen Sprachen eben so schön.
Ihre teutschen Briefe waren musterhaft. Im Zeichnen, in der Musik,
der Laute, und besonders im Klavier, hatte sie eine solche Fertigkeit
erlangt, daß, wenn sie sich am Flügel sezte, selbst Virtuosen sie
bewundern musten. Ihre herablassende Güte des Herzens kam auch
den gerigsten ihrer Mitmenschen mit Achtung zuvor, und fesselte alle,
die sie sahen und sprachen. [“Skizzen” 1805, 165]

Thus in addition to French, she spoke English and Italian with
the facility and elegance of a native, and wrote in these languages
just as beautifully. Her German letters were exemplary. In drawing,
in music, the lute and especially the keyboard, she had achieved
such facility, that when she sat down at the instrument, even virtuosi
had to marvel. Her humble goodness of heart approached even the
lowliest of her fellow beings with respect, and captivated all who saw
her and spoke to her.

A portrait of the Callenberg family by Georg Melchior Kraus shows the family making music, with one sister at the keyboard and the other with what may be a swan-necked lute. The painting is dated to 1773; if the date is accurate, then Louise was already married: she had married in Muskau on 10 Jan 1772; Henriette, seven years older, did not marry until 1774. It may be, then, that the man with the violin is Louise’s husband, Baron Wilhelm Christoph Diede zum Fürstenstein. The standing man in the red coat holding a flute is probably their brother, Count Georg Alexander Heinrich Herrmann von Callenberg.

Louise died on 29 Aug 1803 in Bassano, Italy, just after her fifty-first birthday. Henriette also died relatively young, on 17 Feb 1799, having just turned fifty-four. In 1800, Henriette’s husband published a 445-page biography and eulogy of his wife (Lippe-Weißenfeld 1800). Its title page includes an engraved portrait of both sisters, identified as “H” and “L”.

In 1763 Zinzendorf had visited his uncle and cousins in Muskau (today Bad Muskau, northeast of Dresden on the modern border with Poland) on his return to Vienna from a journey that had taken him to Berlin, Danzig (Gdansk), and Koenigsberg (Kaliningrad). He arrived in Muskau on 11 Oct 1763. His diary entry for that day notes that Henriette recalled to him his earlier visit in 1753, when she would have been eight years old and Louise still an infant. At the time of Zinzendorf’s visit in 1763, Louise was eleven, and it was probably their first encounter. He writes: “La petite Louise est plus malicieuse que l’autre” (“Little Louise is more mischievous than the other”).

Zinzendorf probably did not see Louise again until she and her husband arrived in Vienna on 21 Nov 1782, during an extended stopover on their way to Italy. The unmarried Zinzendorf was quickly smitten by Louise, and she showed evident affection in return. Already on 25 Nov she visited him at home:

[...]                                                            Ma chere Cousine
Dieden vint passer quelques instans chez moi avant d’aller
chez la P:esse Elisabeth, je la trouvois fort aimable, elle entra dans
mes peines, elle me consola et comprit qu’il me faudroit la Societé
d’une femme, elle prit le Chocolat chez moi. [...]
[Zinzendorf, 25 Nov 1782]

[...]                                                            My dear cousin Diede
came by to visit for a few moments before going to see Princess
Elisabeth. I found her most amiable, she listened to my problems,
she consoled me, and understood that I need the companionship
of a woman; she drank chocolate with me. [...]

(The reference is to fifteen-year-old Princess Elisabeth of Württemberg, whom Joseph II had brought to Vienna to educate as a bride for his nephew, Archduke Franz.) Zinzendorf saw Louise every day between her arrival on 21 Nov 1782 and her departure on 2 Jan 1783, often several times a day at various social events, and he soon fell in love with her. On 30 Nov he writes:

Je passois une heure chez ma Louise fort agréablement.
Elle est heureuse et se sent telle. Son mari lui laisse une
liberté honnete, elle aime Ses enfans qu’elle a remis a M:^e
de Lichtenstein a Gotha. Elle pretend me connoitre parfai-
tement. Le bas du visage est charmant, la bouche belle, les
dents blanches. [...] [Zinzendorf, 30 Nov 1782]

I spent a very pleasant hour with my Louise. She is happy
and feels it so. Her husband allows her decent freedom.
She loves her children, whom she left with Madame von
Lichtenstein in Gotha. She claims to understand me perfectly.
The lower part of her face is charming, her mouth beautiful,
her teeth white. [...]

Early on 5 Dec he is disappointed not to find Louise alone when he goes to visit her. Later that day at Countess von Pergen’s he hears Louise (apparently for the first time) play the keyboard, writing “J’en fus enchanté. M:^e de Dieden joue avec un talent et une expression peu communes” (“I was enchanted. Madame von Diede plays with uncommon talent and expression”). The Emperor, who had not yet met Louise, drops by and is likewise enchanted, talking to Louise about music and the Mozart-Clementi duel a year earlier (see our addendum for 5 Dec 1782).

Zinzendorf’s encounter with Louise on 6 Dec is described in the diary entry transcribed at the top of this page. The following day he is agitated after seeing Louise again:

[...]                            je quittois la compagnie aflligé de
l’idée que je ne suis point heureux, qu’il me manque
un etre femelle qui s’interesse vivement a mon Sort. Cette
idée est inutile et par conséquent absurde. Elle empoisonne
mon cœur, elle le ferme au bonheur, le plus chéri. [...]
[Zinzendorf, 7 Dec 1782]

[...]                             I left the company distressed by the
idea that I am not happy, that I miss having a female
person who takes a lively interest in my fate. This idea is
useless and consequently absurd. It poisons my heart and
closes it to the most cherished happiness. [...]

Two days later he writes:

[...]                 Au souper du P:^ce de Paar. Louise y vint
tard, elle etoit si belle, que la flamme un peu amortie au diner
d’aujourd’hui^^matin chez Pellegrini se ralluma de nouveau, je me sentis l’aimer plus
que jamais. [...] [Zinzendorf, 9 Dec 1782]

[...]                 To supper at Prince Paar’s. Louise arrived late.
She was so beautiful, that the flame that had dimmed a bit at
dinner today^^{this morning} at Pellgrini’s, was rekindled anew. I felt more in love
with her than ever. [...]

Zinzendorf remained preoccupied with Louise for the rest of the month. He heard her play the keyboard again on 27 Dec at Madame Buquoy’s (“Louise y joua comme un ange”; “Louise played like an angel”). On 1 Jan 1783, the day before her departure for Italy, he writes:

[...]                                          J’assistois a la toilette de Louise qui fut
enchantée de mon projet de l’aller voir avec Henriette, je lui dis que si
jamais elle etoit veuve, elle devroit s’etablir ici ou je serois enchanté
[de] partager ma fortune avec elle. Louise m’assura d’une maniere char=
mante que cet evenement la rendroit tres malheureuse, mais qu’elle
avoit en moi cette confiance pleniere de ne pouvoir s’attendre de ma
part qu’a des procedés genereux. [Zinzendorf, 1 Jan 1783]

[...]                                         I attended the toilette of Louise, who was
delighted by my plan to come see her with Henriette. I said to her that
if she were ever a widow, she should settle here, where I would be delighted
to share my fortune with her. Louise assured me in a charming manner that
this event would make her very unhappy, but that she had complete
confidence in me not to expect anything from me except generous treatment.

Louise came to Vienna again on 19 Dec 1785 (Link 1998, 260), remaining for several months. Zinzendorf saw her fairly often, but the intense flame had cooled. By that time, his affections had shifted to Countess Maria Josepha “Henrietta” von Auersperg, née Lobkowitz, yet another married woman.

Because Louise von Diede had arrived in Vienna on 21 Nov 1782, just fifteen days before Zinzendorf heard her play “difficult pieces” by Mozart, it seems likely that these pieces were already in her repertoire by the time of her arrival. While we do not know precisely which keyboard works by Mozart might have been available to her, the number of his mature keyboard works that had appeared in print by that point was quite small: the variations K. 179 (on a minuet by Fischer), K. 180 (“Mio caro Adone”), and K. 354 (“Je suis lindor”), all first published in 1778; and the sonatas K. 309 (C Major), K. 310 (A Minor), and K. 311 (D Major), all published in 1781. Louise’s “Bach” was probably Carl Philipp Emanuel, but we should not rule out Johann Sebastian.

In February 1788, Goethe (somewhat begrudgingly) heard Louise play an “important concerto” (“bedeutendes Concert”) in Rome at the residence of senator Conte Rezzonico on the Capitoline Hill, at an event organized by Goethe’s friend, composer and violinist Philipp Christoph Kayser (1755–1823):

Der Senator von Rom, Graf Rezzonico, war
schon früher, aus Deutschland zurückkehrend, mich
zu besuchen gekommen. Er hatte eine innige Freund=
schaft mit Herrn und Frau von Diede errichtet und
brachte mir angelegentlich Grüße von diesen wer=
then Gönnern und Freunden; aber ich lehnte, wie
herkömmlich, ein näheres Verhältniß ab, sollte aber
doch endlich unausweichlich in diesen Kreis gezogen
werden.
    Jene genannten Freunde, Herr und Frau von
Diede machten ihrem werthen Lebensgenossen einen
Gegenbesuch, und ich konnte mich um so weniger ent=
brechen mancherlei Art von Einladungen anzuneh=
men, als die Dame, wegen des Flügelspiels berühmt,
in einem Concerte auf der capitolinischen Wohnung
des Senators sich hören zu lassen willig war, und
man unsern Genossen Kayser, dessen Geschicklichkeit
ruchtbar geworden, zu einer Teilnahme an jenen
Exhibitionen schmeichelhaft engeladen hatte. Die
unvergleichliche Aussicht bei Sonnenuntergang aus
den Zimmern des Senators nach dem Coliseo zu
mit allem dem was sich von deen andern Seiten an=
schließt, verlieh freilich unserm Künstlerblick das
herrlichste Schauspiel, dem man sich aber nicht hin=
geben durfte, um es gegen die Gesellschaft an Ach=
tung und Artigkeit nicht fehlen zu lassen. Frau von
Diede spielte sodann, sehr große Vorzüge entwi=
ckelnd, ein bedeutendes Concert [...]
[Goethe 1829, 287–88]

[translation:]

The Roman senator Conte Rezzonico, on returning
from Germany, had already come to visit me. He had
established an intimate friendship with Herr and Frau
von Diede, and brought me particular greetings from
these worthy patrons and friends; as was my custom,
however, I declined a closer relationship, but in the end
was drawn inescapably into this circle.
    Said friends, Herr und Frau von Diede, paid a return
visit to their worthy countryman, and I could still less
forbear to accept this sort of invitation, as the lady,
famous for her keyboard playing, was willing to
play in a concert at the Senator’s residence on the
Capitoline, and our comrade Kayser, whose skill had
become well known, had flatteringly been invited to
take part in this exhibition. The incomparable view
at sundown from the senator’s rooms toward the
Coliseum, along with everything that adjoined to it
on all sides, presented our artist’s eye with the
most magnificent prospect—in which one could not
indulge, however, in order not to want in attention and
courtesy to the company. Frau von Diede then played,
demonstrating great merit, an important concerto [...]

At least one composition is attributed to Louise von Diede, a Sonata in D Major for keyboard, in a manuscript collection in the Thurn und Taxis Hofbibliothek in Regensburg.

“Madame Oeynhausen”, at whose residence Zinzendorf heard Louise play Mozart and Bach, was Leonor de Almeida Portugal (1750–1839), wife of Count Carl August von Oeynhausen (1736–1793). In 1775, Oeynhausen had escaped confinement in Berlin, fleeing to Portugal, where he entered government service. From 1780 to 1784 he was Portuguese minister plenipotentiary to the court in Vienna, where his wife became one of the stars of the aristocratic social scene. A fascinating woman in her own right, Countess Oeynhausen was a poet and painter. Her Obras poeticas were published in 1844, and she remains a figure of note in Portuguese literary history.

“Count Philippe” at Oeynhausen’s on the evening of 6 Dec 1782 was probably Count Philipp Joseph von Sinzendorf (1726–1788).

The good news that Zinzendorf conveyed to Louise’s husband Count Wilhelm Christoph on 6 Dec was that the Emperor—with whom Zinzendorf had had a long talk earlier in the day and who had been charmed by Louise the day before (see our entry for 5 Dec 1782)—had granted Diede an audience to talk about the tiny Burggrafschaft Friedberg in Hesse, where Wilhelm was Burgmann.

Zinzendorf is sometimes portrayed as having been rather unmusical and even a bit philistine, but an examination of his diary from 1760, when he was a student in Jena, shows that he practiced keyboard assiduously at that time. He continued to play at least occasionally for some years after.