A woman of no importance.

Take a good look at this family portrait. You could be forgiven for thinking that this is a typical well-heeled family of the early renaissance era; doting Dad, ever-patient Mum and four perfectly-behaved children and grandchildren.
OK. Here's the backstory. Dad will become the Holy Roman Emperor, Maximilian I. Mum is Mary of Burgundy, daughter of the Duke of Burgundy. By marrying Mary (aka Mary the Rich), Maximilian could expect to inherit the dukedom of Burgundy when Mary's father died. The children are variously, the son Philip "the handsome", and grandsons Charles, Ferdinand and Louis (adopted, again in hope of adding more land to the family empire), heir to the kingdoms of Hungary and Bohemia.
Maximilian is nothing if not an empire-builder.
But for now, our concern is not with Maximilian, but with his second wife (Mary of Burgundy died in March of 1482).
In 1494 Maximilian took Bianca Maria Sforza, daughter of the Duke of Milan, as his wife. Bianca's life up to that point hadn't been easy; when she was only four years old, her father had been murdered while attending church. Traditionally a woman was of more importance than an animal, but less importance than a man. In all probability she had no say in choosing her husband, but negotiations were carried out by the Duchy court of Milan. She was only 18 years old.
The purpose of our visit to Innsbruck, 1510, is sadly to bid farewell to Bianca Maria. Such contributions as she has made historically are easily outshone by the magnificence of her husband, Maximilian, who had inherited the title of Holy Roman Emperor in 1493 when his father Frederick III died.
The title of Holy Roman Emperor made Maximilian the official Protector of the Catholic Church, and a subdeacon. For this reason, there could be no Empress of the Holy Roman Empire.
Maximilian's magnificent court has employed the greatest artists and musicians of the age, among them Albrecht Durer, whose portrait of the Emperor below, was painted after Maximilian's death, and Heinrich Isaak. The pomegranate which the Emperor holds is cut open to show the many seeds, symbolic of his wealth and power. Also, take a look at that lower lip. Although it is less obvious in this generation, Maximilian is the founder of the powerful Habsburg dynasty who would later rule from Spain, as well as creating the internationally famous riding school where Lippizaner horses are bred and trained.
Isaak created two settings of a popular song of the time, in much the same way that Elton John adapted his "Candle in the Wind" as "Goodbye, England's Rose" for the memorial service for Princess Diana of England. The first version is better known: "Innsbruck, ich muss dich lassen", or Innsbruck, I must leave thee.
The second version, "Welt, ich muss dich lassen" might have been written as a farewell to Bianca Maria although at the time of her death Isaak had accepted a post in Fiorenza, Italy, after leaving the Imperial court.

Welt, ich muss dich lassen

X:11 % number
T:Welt, ich muss dich lassen % title
C:Heinrich Isaak % composer
O:Transcribed by Moriwaki Michio for the Choral Public Domain Library (www.cpdl.org) % origin.
M:C| % meter
L:1/4 % length of shortest note
Q: % tempo
K:F % key
V:1 name="Superius" sname="Sup." clef="Treble" % voice 1
V:2 name="Contratenor" sname="Ct." clef="Treble"
V:3 name="Tenor" sname="T." clef="Treble"
V:4 name="Bassus" sname="B" clef="Bass"
%=================================================
V:1
z2 F2 | F G A2 | c2 B2 | A2 z A | c>B G2 |
w:O Welt, ich muss dich las-sen, ich fahr da-hin
V:2
c4 | d e f2 | c f2 e | f2 z c | A A B2 |
w:O Welt, ich muss dich las--sen, ich fahr da-hin
V:3
z2 F2 | A B c2 | A2 B2 | c2 z c | c>d _e2 |
w:O Welt, ich muss dich las-sen, ich fahr da-hin
V:4
F,4 | D, G, F, A, | A, G,/F,/ G,2 | F,2 z F, | F, F, _E,2 |
w:O Welt, ich muss dich las---sen, ich fahr da-hin
%== 6 ==
V:1
A2 F2 | E2 z F | G F E F | G2 z G | F G A2 | c2 B2 |
w:mein Stras-sen ins e-wig Va-ter-land. Mein Geist will ich auf-ge-
V:2
A A2 G/F/ | G2 z d | d d c d | B2 z d | d e f2 | c f2 e |
w:mein Stras-sen ins e-wig Va-ter-land. Mein Geist will ich auf-ge-
V:3
d c2 =B | c2 z A | B A G A | G2 z G | A B c2 | A2 B2 |
w:mein Stras-sen ins e-wig Va-ter-land. Mein Geist will ich auf-ge-
V:4
F,2 D,2 | C,2 z D, | G,, D, E, D, | G,,2 z G, | D, G, F, A, | A, G,/F,/ G,2 |
w:mein Stras-sen ins e-wig Va-ter-land. Mein Geist will ich auf-ge-
%==12==
V:1
A2 z A | c>B G2 | A2 F2 | E2 z E | F G A2 | [L:1/8] B3 AGF G2-|
w:ben, da-zu mein Leib und Le-ben set-zen in Got-
V:2
f2 z c | A A B2 | A A2 G/F/ | G2 z g | f e f2 | [L:1/8] f3 edc d2 |
w:ben, da-zu men Leib und Le---ben set-zen_ in Got-
V:3
c2 z c | c>d _e2 | d c2 =B | c2 z c | A B c2 | [L:1/8] d2 B3 AGF |
w:ben, da-zu mein Leib und Le--ben set-zen in Got-
V:4
F,2 z F, | F, F, _E,2 | F,2 D,2 | C,2 z C, | D, G, F,2 | B,,2 z B,, |
%== 18 ==
V:1
[L:1/4] G/F/ F2 E | F2 z E | F G A2 | [L:1/8] B3 AG F G2 | [L:1/4/] G/F/ F2 E | F4 |]
w:-tes gnad-ge Hand, set-zen in Got-------tes gnad-ge Hand.
V:2
[L:1/4] c B c c | c2 z g | f e f2 | [L:1/8] f3 edc d2 | [L:1/4] c B c c | A4 |]
w:-tes gnad-ge Hand, set-zen in_ Got------tes gnad-ge Hand.
V:3
[L:1/4] E F G G | F2 z c | A B c2 | [L:1/8] d2 B3 A/G/F/ | [L:1/4] E F G G | F4 |]
w:-tes gnad-ge Hand, set-zen in Got-------tes gnad-ge Hand.
V:4
[L:1/4] C, D, C, C, | F,,2 z C, | D, G, F,2 | B,,2 z B,, | C, D, C, C, | F,,4 |]
w:Got-tes gnad-ge Hand, set-zen in Got-tes, in Got-tes gnad-ge Hand.

Approximate translations
O world I must leave thee, I my road leads there, into my eternal home. My spirit fails me, and so do my life and health I offer myself into the hand of God.	Innsbruck, I must leave thee, my road leads there, into a foreign country. My beloved has gone there before me, My countenance is pale in my misery.

Compare that, with the original song:

Innsbruck, ich muss dich lassen

X:12 % number
T:Innsbruck, ich muss dich lassen % title
C:Heinrich Isaak % composer
O:Choral Public Domain Library
O:Http://www.cpdl.org % origin.
M:C| % meter
L:1/4 % length of shortest note
Q: % tempo
K:F % key
V:1 name="Soprano" sname="S." % voice 1
V:2 name="Alto" sname="A."
V:3 name="Tenor" sname="T."
V:4 name="Bass" sname="B." clef="bass"
%
V:1
z2 F2 | F G A2 | c2 B2 | A2 z A | c>B G2 |
w:Inns-bruck, ich muss dich las-sen, ich fahr da-hin
V:2
C4 | D E F2 | C F2-E | F2 z C | A, A, B,2 |
w:Inns-bruck, ich muss dich las-sen, ich fahr da-hin
V:3
z2 F2 | A B c2 | A2 B2 | c2 z c | c>d _e2 |
w:Inns-bruck, ich muss dich las-sen, ich fahr da-hin
V:4
F,4 | D, G, F, A, | A, G,/F,/ G,2 | F,2 z F, | F, F, _E,2 |
w:Inns-bruck, ich muss dich las----sen, ich fahr da-hin
%== 6 ==
V:1
A2 F2 | E2 z F | G F E F | G2 z G | F G A2 | c2 B2 |
w:mein Stras-sen in Frem-de land da-hin. Mein Freud ist mir ge-nom-
V:2
A, A,2 G,/F,/ | G,2 z D | D D C D | B,2 z D | D E F2 | C F2-E |
w:mein Stras----sen in frem-de land da-hin. Mein Freud ist mir ge-nom-
V:3
d c2 =B | c2 z A | B A G A | G2 z G | A B c2 |A2 B2 |
w:mein Stras--sen in frem-de land da-hin. Mein Freud ist mir ge-nom-
V:4
F,2 D,2 | C,2 z D, | G,, D, E, D, | G,,2 z G, | D, G, F, A, | A, G,/F,/ G,2 |
w:mein Stras-sen in frem-de land da-hin. Mein Freud ist mir ge-nom-
%== 12 ==
V:1
A2 z A | c>B G2 | A2 F2 | E2 z E | F G A2 | B>A G/F/ G-|
w:men, die ich nit weiss be-kom-men, wo ich im E-
V:2
F2 z C | A, A, B,2 | A, A,2 G,/F,/ | G,2 z G | F E F2-| F>E D/C/ D |
w:men, die ich nit weiss be-kom---men, wo ich im E-
V:3
c2 z c | c>d _e2 | d c2-=B | c2 z c | A B c2 | d B>A G/F/ |
w:men, die ich nit weiss be-kom--men, wo ich im E-
V:4
F,2 z F, | F, F, _E, | F,2 D,2 | C,2 z C, | D, G, F,2 | B,,2 z B,, |
w:men, die ich nit weiss be-kom-men, wo ich im E-lend, im
%== 18 ==
V:1
G/F/ F2 E | F2 z E | F G A2 | B>A G/F/ G-|G/F/ F2 E | F4 |]
w:---lend bin, wo ich im E---------lend bin.
V:2
C B, C2 | C2 z G | F E F2-|F>E D/C/ D | C B, C2 | A,4 |]
w:--lend bin, wo ich im E--------lend bin.
V:3
E F G2 | F2 z c | A B c2 | d B>A G/F/ | E F G2 | F4 |]
w:--lend bin, wo ich im E--------lend bin.
V:4
C,-D, C,2 | F,,2 z C, | D, G, F,2 | B,,2 z B,, | C,-D, C,2 | F,,4 |]
w:E--lend bin, wo ich im E-lend, im E--lend bin.
W:
W:Gross Leid muss ich jetzt tragen, das ich allein
W:tu klagen dem liebsten Buhlen mein. Ach Lieb, nun lass mich armen
W:im Herzen dein Erbarmen, dass ich muss dannen sein, dass ich muss dannen sein.
W:
W:Mein Trost ob allen Weiben Dein tu ich ewig
W:bleiben stet treu, der Ehren fromm. Nun muss dich Gott bewahren
W:in aller Tugend sparen, bis dass ich wieder komm, bis dass ich weider komm!

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