When the first chord of the brief, passionate introduction was first heard in a theatre nearly half a century ago, it sent a shudder through every professional class-room in every conservatoire in Europe, and the theme is perhaps the most important in the act (j); and the cutting, almost raucous chord lets us know at once that big doings are at hand.  Another theme follows—­one of impatience and sick anxiety:  it is that which is played again when Isolda, hardly able to contain herself while waiting for Tristan, wildly waves her handkerchief, beckoning to him.  Another and most lovely melody is heard (k); and then some of the love-music which is played when he does come and rushes to her arms.  This leads straight to the rising of the curtain, and Brangaena is seen on the steps by the torch, keeping watch and listening to the horns of a hunting party; the sounds are growing fainter in the distance.

Isolda enters, and Brangaena vainly tries to dissuade her from meeting Tristan.  This night hunt, she swears, is a scheme of Melot’s for the betrayal of Tristan, his foe.  Isolda laughs.  Melot is Tristan’s friend, and the night hunt was arranged that the lovers might meet.  They dispute to some of Wagner’s loveliest melodies.  The theme (k) flows along as an accompaniment, and becomes more prominent when Isolda says she can no longer hear the horns; she hears the gentle plash of the brook running from the fountain—­as “in still night alone it laughs on my ear”—­the party of hunters must be many miles off.  The signal for Tristan is the extinguishing of the torch, and the music associated with this deed now is used again in the last act in another form.  Brangaena prays her mistress not to put it out:  it means death, she says, and as a sort of subsidiary death-theme this melody is afterwards used.  Isolda is too completely mastered by desire to listen.  When Brangaena curses herself for having changed the magic drinks she is laughed at.  To music filled with passion and of perfect beauty she says the whole business was arranged by Venus, goddess of love, and we hear yet another love-theme (l); then to the crash of what we must call the torch-theme, blent with the death-theme from Act I, she throws down the torch and frantic with impatience awaits her lover.

He enters, and after some delirious pages not to be described in words the pair fall to talk in Schopenhauerian terminology about the light and the dark.  But the passion never goes out of the music.  On the contrary, it grows in intensity, for the madness of the meeting is nothing to the white-hot passion we get later; and in spite of the terminology the meaning of both Tristan and Isolda is perfectly clear.  Light has been, and is, the enemy of their love; in the garish light of day Tristan, filled with daylight dreams of ambition, first made over to Mark, so to speak, his rights in Isolda; “is there a pain or a woe that does not awaken with daylight?”