The subject of _Tristan und Isolde_ was first mentioned by Wagner in a
letter to Liszt in the latter part of 1854; the poem was written at
Zürich in the summer of 1857, and finished in September of that year.
The composition of the first act was completed at Zürich, December 31,
1857 (some say, but only in the sketch); the second act was completed at
Venice in March, 1859; the third act at Lucerne in August, 1859.
Wagner himself frequently conducted the prelude and Love-Death, arranged
by him for orchestra alone, in the concerts given by him in 1863. At
those given in Carlsruhe and Löwenberg the programme characterized the
prelude as _Liebestod_ and the latter section, now known as _Liebestod_,
as _Verklärung_ (Transfiguration).
The prelude, _langsam und schmachtend_ (slow and languishingly), in A
minor, 6-8, is a gradual and long-continued _crescendo_ to a most
sonorous _fortissimo_; a shorter _decrescendo_ leads back to
_pianissimo_. It is free in form and of continuous development. There
are two chief themes: the first phrase, sung by violoncellos, is
combined in the third measure with a phrase ascending chromatically and
given to the oboes.
These phrases form a theme known as the “Love Potion” motive, or the
motive of “Longing”; for passionate commentators are not yet agreed
about the terminology. The second theme, again sung by the violoncellos,
a voluptuous theme, is entitled “Tristan’s Love Glance.”
The prelude is scored for three flutes (and piccolo), two oboes, English
horn, two clarinets, bass clarinet, three bassoons, four horns, three
trumpets, three trombones, bass tuba, kettledrums, harp, and the usual
strings.
Wagner wrote this explanatory programme:
“A primitive old love poem, which, far from having become extinct, is
constantly fashioning itself anew, and has been adopted by every
European language of the Middle Ages, tells us of Tristan and Isolde.
Tristan, the faithful vassal, woos for his king her for whom he dares
not avow his own love, Isolde. Isolde, powerless to do otherwise than
obey the wooer, follows him as bride to his lord. Jealous of this
infringement of her rights, the Goddess of Love takes her revenge. As
the result of a happy mistake, she allows the couple to taste of the
love potion which, in accordance with the custom of the times, and by
way of precaution, the mother had prepared for the husband who should
marry her daughter from political motives, and which, by the burning
desire which suddenly inflames them after tasting it, opens their eyes
to the truth and leads to the avowal that for the future they belong
only to each other. Henceforth, there is no end to the longings, the
demands, the joys and woes of love. The world, power, fame, splendor,
honor, knighthood, fidelity, friendship, all are dissipated like an
empty dream. One thing only remains: longing, longing, insatiable
longing, forever springing up anew, pining and thirsting. Death, which
means passing away, perishing, never awakening, their only
deliverance.... Powerless, the heart sinks back to languish in longing,
in longing without attaining; for each attainment only begets new
longing, until in the last stage of weariness the foreboding of the
highest joy of dying, of no longer existing, of the last escape into
that wonderful kingdom from which we are furthest off when we are most
strenuously striving to enter therein. Shall we call it death? Or is it
the hidden wonder-world from out of which an ivy and vine, entwined with
each other, grew up upon Tristan’s and Isolde’s grave, as the legend
tells us?”