There are typical themes in the score, but they are hardly handled with the varied effect that entitles them to be called leading motives. On the other hand there are fascinating details of orchestration. These are important because the composer has given significant clang-tints to the music that is heard in connection with the different characters in the story. He uses the brass chiefly to accompany the King, and, of course, the martial choruses; the plaintive, yet spiritual high wood-wind for Elsa; the English horn and sombre bass clarinet—the instrument that had to be bought—for Ortrud; the violins, especially in high harmonic positions, to indicate the Grail and its representative, for Lohengrin is a Knight of the Holy Grail. Even the keys employed are distinctive. The Herald's trumpeters blow in C and greet the King's arrival in that bright key. F-sharp minor is the dark, threatful key that indicates Ortrud's appearance. The key of A, which is the purest for strings and the most ethereal in effect, on account of the greater ease of using "harmonics," announces the approach of Lohengrin and the subtle influence of the Grail.
Moreover Wagner was the first composer to discover that celestial effects of tone colour are produced by the prolonged notes of the combined violins and wood-wind in the highest positions more truly than by the harp. It is the association of ideas with the Scriptures, wherein the harp frequently is mentioned, because it was the most perfected instrument of the period, that has led other composers to employ it for celestial tone-painting. But while no one appreciated the beauty of the harp more than Wagner, or has employed it with finer effect than he, his celestial tone-pictures with high-violins and wood-wind are distinctly more ecstatic than those of other composers.
The music clothes the drama most admirably. The Vorspiel or Prelude immediately places the listener in the proper mood for the story which is to unfold itself, and for the score, vocal and instrumental, whose strains are to fall upon his ear.
The Prelude is based entirely upon one theme, a beautiful one and expressive of the sanctity of the Grail, of which Lohengrin is one of the knights. Violins and flutes with long-drawn-out, ethereal chords open the Prelude. Then is heard on the violins, so divided as to heighten the delicacy of the effect, the Motive of the Grail, the cup in which the Saviour's blood is supposed to have been caught as it flowed from the wound in His side, while he was on the Cross. No modern book on orchestration is considered complete unless it quotes this passage from the score, which is at once the earliest and, after seventy years, still the most perfect example of the effect of celestial harmony produced on the high notes of the divided violin choir. This interesting passage in the score is as follows:
Although this is the only motive that occurs in the Prelude, the ear never wearies of it. Its effectiveness is due to the wonderful skill with which Wagner handles the theme, working it up through a superb crescendo to a magnificent climax, with all the splendours of Wagnerian orchestration, after which it dies away again to the ethereal harmonies with which it first greeted the listener.
Act I. The curtain, on rising, discloses a scene of unwonted life on the plain near the River Scheldt, where the stream winds toward Antwerp. On an elevated seat under a huge oak sits King Henry I. On either side are his Saxon and Thuringian nobles. Facing him with the knights of Brabant are Count Frederick of Telramund and his wife, Ortrud, daughter of the Prince of Friesland, of dark, almost forbidding beauty, and with a treacherous mingling of haughtiness and humility in her carriage.
It is a strange tale the King has just heard fall from Frederick of Telramund's lips. Henry has assembled the Brabantians on the plain by the Scheldt in order to summon them to join his army and aid in checking the threatened invasion of Germany by the Hungarians. But he has found the Brabantians themselves torn by factional strife, some supporting, others opposing Frederick in his claim to the ducal succession of Brabant.