The music of the first act is largely fierce, angry, turbulent, often bitter music, blent and merging into music expressive of fierce desire, the hunger of the man after the woman, of the woman after the man. There is one moment of sweet longing--the moment after Isolda and Tristan have drunk the fatal potion; but instantly the torrent breaks forth, and though it is in a way sweet, the sweetness is mixed with fire; the stream is as a stream of molten lava, scalding, consuming. The note of the music to the second act is utterly different; there is fire, indeed, a golden fire; there is greedy impatience and restlessness; but the fire does not scorch nor scald, the impatience is not despairing, the love is not--as it certainly is in the first act--that passion which is but one remove from deadly hate. Almost at the beginning of the first act Isolda, devoured by a longing for revenge, schemed to murder Tristan, and she does not falter in her purpose until he has taken the drink; the reaction has all the violence of a cataclysm; all is delirium; there is not a moment of happy lingering over the joy of a possible; new life; there is no time for that, no thought of it. All is burning wrath and hate and equally burning lust and greed for the possession of the beloved one's body. In the second act the anger has died out, and in the whirl of the music, though at its maddest, there is a fulness, an assured sense of coming satisfaction; and the excitement settles down into long, drawn-out, luscious, voluptuous strains as the lovers, held in each other's arms, exchange the sweet confidences usual (I suppose) on such occasions. Musically the act may be regarded--conveniently, though roughly and crudely--as a kind of symphony, in four sections which to an extent overlap. We have section one from the first bar of the prelude to Tristan's entry; section two, the impassioned duet; three, from the hymn to night until the lovers are discovered; and four, from that point to the end. Many of the themes are worked right through, but the sections vary vastly in colour, atmosphere and feeling. The variety unified into a completely satisfying whole is astounding. Amongst the really great musicians only four possessed the organising brain in this degree--Wagner himself, Beethoven, Handel and Bach. This act is even more completely an organic whole than the first; every part performs its functions and retains its individuality, yet all the parts are co-ordinated. I have seen miraculous pieces of machinery in which each part seemed to be alive and doing its duty independent of the others; yet all working together to achieve one purpose. The score of _Tristan_ is as marvellous--indeed, more so, for the purpose is not a mechanical one, but the expression, with rigid fidelity to truth, of the most subtle and exquisite feelings.