To come back to the prelude:
An ardent longing for the unattainable; a consuming hunger
"——which doth make
The meat it feeds on;"
a desire that cannot be quenched, yet will not despair; finally, at the lowest ebb of the sweet agony, the promise of an end of suffering, in self-forgetfulness, oblivion, annihilation of individual identity, and hence in a blending or union of identity—these, according to Wagner's exposition and the play itself, are the elements which are prefigured in the instrumental introduction. What are their musical symbols?
The fundamental theme of the drama, the kernel of its musical development, is the phrase which we hear at the beginning of the prelude:
![[PNG]](#9173371841954810646_p48_s_au.png.id-1174723580773767852.wrap-0.html.html){kind=link}
Brief as this is, it illustrates one step in the melodic development, in respect of which "Tristan und Isolde" is Wagner's most marvellous achievement. It is a unit, in so far as it stands for the passion of the pair, in both its aspects of blissful longing and infinite suffering, but it is nevertheless already complex. It is two-voiced. One voice descends chromatically, the other (beginning with the third measure) ascends by similar degrees. A figure like that used in music to indicate a crescendo,