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The Ring Cycle

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The Ring Cycle

Der Ring des Nibelungen (The Ring of the Nibelung) is a cycle of four epic operas by the German composer Richard Wagner (1813–1883). The works are based loosely on characters from the Norse sagas and the Nibelungenlied. The composer termed the cycle a "Bühnenfestspiel" (stage festival play), structured in three days preceded by a Vorabend ("ante-evening"). It is often referred to as the Ring Cycle, Wagner's Ring, or simply the Ring.

Wagner wrote the libretto and music over the course of about twenty-six years, from 1848 to 1874. The four operas that constitute the Ring cycle are, in sequence:

Although individual operas of the sequence are sometimes performed separately, Wagner intended them to be performed in series. The first performance as a cycle opened the first Bayreuth Festival in 1876, beginning with Das Rheingold on 13 August and ending with Götterdämmerung on 17 August.


Wagner's title is most literally rendered in English as The Ring of the Nibelung. The Nibelung of the title is the dwarf Alberich, and the ring in question is the one he fashions from the Rhine Gold. The title therefore denotes "Alberich's Ring".[1] The "-en" suffix in "Nibelungen" can occur in either a genitive singular or a plural, but the article "des" immediately preceding makes it clear that the singular is here intended. "Nibelungen" is occasionally mistaken as a plural, but the Ring of the Nibelungs (in German Der Ring der Nibelungen) is incorrect.


The cycle is a work of extraordinary scale. Perhaps the most outstanding facet of the monumental work is its sheer length: a full performance of the cycle takes place over four nights at the opera, with a total playing time of about 15 hours, depending on the conductor's pacing. The first and shortest opera, Das Rheingold, typically lasts two and a half hours, while the final and longest, Götterdämmerung, takes up to five hours, excluding intervals. The cycle is modelled after ancient Greek dramas that were presented as three tragedies and one satyr play. The Ring proper begins with Die Walküre and ends with Götterdämmerung, with Rheingold as a prelude. Wagner called Das Rheingold a Vorabend or "Preliminary Evening", and Die Walküre, Siegfried and Götterdämmerung were subtitled First Day, Second Day and Third Day, respectively, of the trilogy proper.

The scale and scope of the story is epic. It follows the struggles of gods, heroes, and several mythical creatures over the eponymous magic Ring that grants domination over the entire world. The drama and intrigue continue through three generations of protagonists, until the final cataclysm at the end of Götterdämmerung.

The music of the cycle is thick and richly textured, and grows in complexity as the cycle proceeds. Wagner wrote for an orchestra of gargantuan proportions, including a greatly enlarged brass section with new instruments such as the Wagner tuba, bass trumpet and contrabass trombone. Remarkably, he uses a chorus only relatively briefly, in acts 2 and 3 of Götterdämmerung, and then mostly of men with just a few women. He eventually had a purpose-built theatre constructed, the Bayreuth Festspielhaus, in which to perform this work. The theatre has a special stage that blends the huge orchestra with the singers' voices, allowing them to sing at a natural volume. The result was that the singers did not have to strain themselves vocally during the long performances.

List of characters

Gods Mortals Valkyries Rhinemaidens, Giants & Nibelungs Other characters
  • Wotan, King of the Gods (god of light, air, and wind) (bass-baritone)
  • Fricka, Wotan's wife, goddess of marriage (mezzo-soprano)
  • Freia, Fricka's sister, goddess of love, youth, and beauty (soprano)
  • Donner, Fricka's brother, god of thunder (baritone)
  • Froh, Fricka's brother, god of spring/happiness (tenor)
  • Erda, goddess of wisdom/fate/Earth (contralto)
  • Loge, demigod of fire (tenor in Das Rheingold, represented instrumentally elsewhere)
  • The Norns, the weavers of fate, daughters of Erda (contralto, mezzo-soprano, soprano)



  • Hunding, Sieglinde's husband, chief of the Neidings (bass)


  • Gunther, King of the Gibichungs, son of King Gibich and Queen Grimhilde (baritone)
  • Gutrune, his sister (soprano)
  • Hagen, their half-brother, son of Alberich and Queen Grimhilde (bass)
  • A male choir of Gibichung vassals and a small female choir of women
  • Brünnhilde (soprano)
  • Waltraute (mezzo-soprano)
  • Helmwige (soprano)
  • Gerhilde (soprano)
  • Siegrune (mezzo-soprano)
  • Schwertleite (mezzo-soprano)
  • Ortlinde (soprano)
  • Grimgerde (mezzo-soprano)
  • Rossweisse (mezzo-soprano)


  • Woglinde (soprano)
  • Wellgunde (soprano)
  • Flosshilde (mezzo-soprano)



  • Alberich (baritone)
  • Mime, his brother, and Siegfried's foster father (tenor)
  • The Voice of a Woodbird (soprano)


The plot revolves around a magic ring that grants the power to rule the world, forged by the Nibelung dwarf Alberich from gold he stole from the Rhine maidens in the river Rhine. With the assistance of the God Loge, Wotan – the chief of the gods – steals the ring from Alberich, who curses it, but is forced to hand it over to the giants, Fafner and Fasolt in payment for building the home of the gods, Valhalla, or they will take Freia, who provides the gods with the golden apples that keep them young. Wotan's schemes to regain the ring, spanning generations, drive much of the action in the story. His grandson, the mortal Siegfried, wins the ring by slaying Fafner (who slew Fasolt for the ring) – as Wotan intended – but is eventually betrayed and slain as a result of the intrigues of Alberich's son Hagen, who wants the ring. Finally, the Valkyrie Brünnhilde – Siegfried's lover and Wotan's daughter who lost her immortality for defying her father in an attempt to save Siegfried's father Sigmund – returns the ring to the Rhine maidens as she commits suicide on Siegfried's funeral pyre, Hagen is drowned as he attempts to recover the ring. In the process, the gods and Valhalla are destroyed.

Details of the storylines can be found in the articles on each opera.

Wagner created the story of the Ring by fusing elements from many German and Scandinavian myths and folk tales. The Old Norse Edda supplied much of the material for Das Rheingold, while Die Walküre was largely based on the Völsunga saga. Siegfried contains elements from the Eddur, the Völsunga saga and Thidrekssaga. The final opera, Götterdämmerung, draws from the 12th-century German poem, the Nibelungenlied, which appears to have been the original inspiration for the Ring.[2]

The Ring has been the subject of myriad interpretations. For example, George Bernard Shaw, in The Perfect Wagnerite, argues for a view of The Ring as an essentially socialist critique of industrial society and its abuses. Robert Donington in Wagner's Ring And Its Symbols interprets it in terms of Jungian psychology, as an account of the development of unconscious archetypes in the mind, leading towards individuation.


In his earlier operas (up to and including Lohengrin) Wagner's style had been based, rather than on the Italian style of opera, on the German style as developed by Carl Maria von Weber, with elements of the grand opera style of Giacomo Meyerbeer. However he came to be dissatisfied with such a format as a means of artistic expression. He expressed this clearly in his essay 'A Communication to My Friends', (1851) in which he condemned the majority of modern artists, in painting and in music, as "feminine ... the world of art close fenced from Life, in which Art plays with herself.' Where however the impressions of Life produce an overwhelming 'poetic force', we find the 'masculine, the generative path of Art'.[3]

Wagner unfortunately found that his audiences were not willing to follow where he led them:

The public, by their enthusiastic reception of Rienzi and their cooler welcome of the Flying Dutchman, had plainly shown me what I must set before them if I sought to please. I completely undeceived their expectations; they left the theatre, after the first performance of Tannhäuser, [1845] in a confused and discontented mood. – The feeling of utter loneliness in which I now found myself, quite unmanned me... My Tannhäuser had appealed to a handful of intimate friends alone.[4]

Finally Wagner announces:

I shall never write an Opera more. As I have no wish to invent an arbitrary title for my works, I will call them Dramas ...

I propose to produce my myth in three complete dramas, preceded by a lengthy Prelude (Vorspiel). ...

At a specially-appointed Festival, I propose, some future time, to produce those three Dramas with their Prelude, in the course of three days and a fore-evening. The object of this production I shall consider thoroughly attained, if I and my artistic comrades, the actual performers, shall within these four evenings succeed in artistically conveying my purpose to the true Emotional (not the Critical) Understanding of spectators who shall have gathered together expressly to learn it.[5]

This is his first public announcement of the form of what would become the Ring cycle.

In accordance with the ideas expressed in his essays of the period 1849–51 (including the "Communication" but also "Opera and Drama" and "The Artwork of the Future"), the four parts of the Ring were originally conceived by Wagner to be free of the traditional operatic concepts of aria and operatic chorus. The Wagner scholar Curt von Westernhagen identified three important problems discussed in "Opera and Drama" which were particularly relevant to the Ring cycle: the problem of unifying verse stress with melody; the disjunctions caused by formal arias in dramatic structure, and the way in which opera music could be organised on a different basis of organic growth and modulation; and the function of musical motifs in linking elements of the plot whose connections might otherwise be inexplicit. This became known as the leitmotif technique, (see below), although Wagner himself did not use this word.[6]

However, Wagner relaxed some aspects of his self-imposed restrictions somewhat as the work progressed. As George Bernard Shaw sardonically (and slightly unfairly)[7] noted of the last opera Götterdämmerung

And now, O Nibelungen Spectator, pluck up; for all allegories come to an end somewhere... The rest of what you are going to see is opera, and nothing but opera. Before many bars have been played, Siegfried and the wakened Brynhild, newly become tenor and soprano, will sing a concerted cadenza; plunge on from that to a magnificent love duet...The work which follows, entitled Night Falls on the Gods [Shaw's translation of Götterdämmerung], is a thorough grand opera.[8]



As a significant element in the Ring and his subsequent works, Wagner adopted the use of leitmotifs. These are recurring themes and/or harmonic progressions. They musically denote an action, object, emotion, character or other subject mentioned in the text and/or presented onstage. Wagner referred to them in "Opera and Drama" as "guides-to-feeling", and described how they could be used to inform the listener of a musical or dramatic subtext to the action onstage in the same way as a Greek chorus did for the theatre of ancient Greece. While other composers before Wagner had already used similar techniques, the Ring was a landmark in the extent to which they were employed, and in the ingenuity of their combination and development.


Wagner made significant innovations in orchestration in this work. He wrote for a very large orchestra, using the whole range of instruments used singly or in combination to express the great range of emotion and events of the drama. Wagner even commissioned the production of new instruments, including the Wagner tuba, invented to fill a gap he found between the tone qualities of the horn and the trombone, as well as variations of existing instruments, such as the bass trumpet and a contrabass trombone with a double slide. He also developed the "Wagner bell", enabling the bassoon to reach the low A-natural, whereas normally B-flat is the instrument's lowest note. If such a bell is not to be used, then a contrabassoon should be employed.

All four operas have a very similar instrumentation. The core ensemble of instruments are one piccolo, three flutes (third doubling second piccolo), three oboes, English horn (doubling fourth oboe), three clarinets, one bass clarinet, three bassoons; eight horns (fifth through eight doubling wagner tubas), three trumpets, one bass trumpet, three trombones, one contrabass trombone (also a bass trombone), one contrabass tuba; a percussion section with 4 timpani (requiring two players), triangle, cymbals, glockenspiel; six harps and a string section consisting of 16 first and second violins, 12 violas, 12 violoncellos, and 8 double basses.

Das Rheingold requires one bass drum, one tam-tam, one onstage harp and 18 onstage anvils. Die Walküre requires one snare drum, tam-tam, and an on-stage steerhorn. Siegfried requires one onstage English horn and one onstage horn. Götterdämmerung requires five onstage horns and three onstage steerhorns.


Much of the Ring, especially from Siegfried act 3 onwards, cannot be said to be in traditionally clearly defined keys for long stretches, but rather in 'key regions', each of which flows smoothly into the following. This fluidity avoided the musical equivalent of clearly defined musical paragraphs, and assisted Wagner in building the work's huge structures. Tonal indeterminacy was heightened by the increased freedom with which he used dissonance and chromaticism. Chromatically altered chords are used very liberally in the Ring, and this feature, which is also prominent in Tristan und Isolde, is often cited as a milestone on the way to Arnold Schoenberg's revolutionary break with the traditional concept of key and his dissolution of consonance as the basis of an organising principle in music.

Composition of the Ring cycle

The text

In summer 1848 Wagner wrote The Nibelung Myth as Sketch for a Drama, combining the medieval sources previously mentioned into a single narrative, very similar to the plot of the eventual Ring cycle, but nevertheless with substantial differences. Later that year he began writing a libretto entitled Siegfrieds Tod ("Siegfried's Death"). He was possibly stimulated by a series of articles in the Neue Zeitschrift für Musik, inviting composers to write a 'national opera' based on the Nibelungenlied, a 12th-century High German poem which, since its rediscovery in 1755, had been hailed by the German Romantics as the "German national epic". Siegfrieds Tod dealt with the death of Siegfried, the central heroic figure of the Nibelungenlied. The idea had occurred to others – the correspondence of Fanny and Felix Mendelssohn in 1840/41 reveals that they were both outlining scenarios on the subject: Fanny wrote 'The hunt with Siegfried's death provides a splendid finale to the second act'.[9]

By 1850, Wagner had completed a musical sketch (which he abandoned) for Siegfrieds Tod. He now felt that he needed a preliminary opera, Der junge Siegfried ("The Young Siegfried", later renamed to "Siegfried"), to explain the events in Siegfrieds Tod. The verse draft of Der junge Siegfried was completed in May 1851. By October, he had made the momentous decision to embark on a cycle of four operas, to be played over four nights: Das Rheingold, Die Walküre, Der Junge Siegfried and Siegfrieds Tod.

The text for all four operas was completed in December 1852, and privately published in February 1853.

The music

In November 1853, Wagner began the composition draft of Das Rheingold. Unlike the verses, which were written as it were in reverse order, the music would be composed in the same order as the narrative. Composition proceeded until 1857, when the final score up to the end of act 2 of Siegfried was completed. Wagner then laid the work aside for twelve years, during which he wrote Tristan und Isolde and Die Meistersinger von Nürnberg.

By 1869, Wagner was living at Tribschen on Lake Lucerne, sponsored by King Ludwig II of Bavaria. He returned to Siegfried, and, remarkably, was able to pick up where he left off. In October, he completed the final opera in the cycle. He chose the title Götterdämmerung instead of Siegfrieds Tod for this opera. In the completed work the gods are destroyed in accordance with the new pessimistic thrust of the cycle, not redeemed as in the more optimistic originally planned ending. Wagner also decided to show onstage the events of Das Rheingold and Die Walküre, which had hitherto only been presented as back-narration in the other two operas. These changes resulted in some discrepancies in the cycle, but these do not diminish the value of the work.


First productions

On King Ludwig's insistence, and over Wagner's objections, "special previews" of Das Rheingold and Die Walküre were given at the National Theatre in Munich, before the rest of the Ring. Thus, Das Rheingold premiered on 22 September 1869, and Die Walküre on 26 June 1870. Wagner subsequently delayed announcing his completion of Siegfried to prevent this opera also being premiered against his wishes.

Wagner had long desired to have a special festival opera house, designed by himself, for the performance of the Ring. In 1871, he decided on a location in the Bavarian town of Bayreuth. In 1872, he moved to Bayreuth, and the foundation stone was laid. Wagner would spend the next two years attempting to raise capital for the construction, with scant success; King Ludwig finally rescued the project in 1874 by donating the needed funds. The Bayreuth Festspielhaus opened in 1876 with the first complete performance of the Ring, which took place from 13 to 17 August.

In 1882,[10] London impresario Alfred Schulz-Curtius organized the first staging in the United Kingdom of the Ring cycle, conducted by Anton Seidl and directed by Angelo Neumann.

The first production of the Ring in Italy was in Venice (the place where Wagner died), just two months after his 1883 death, at La Fenice.[11]

Notable modern productions

The Ring is a major undertaking for any opera company: staging four interlinked operas requires a huge commitment both artistically and financially. In most opera houses, production of a new Ring cycle will happen over a number of years, with one or two operas in the cycle being added each year. The Bayreuth Festival, where the complete cycle is performed most years, is unusual in that a new cycle is almost always created within a single year.

Early productions of the Ring cycle stayed close to Wagner's original Bayreuth staging. Trends set at Bayreuth have continued to be influential. Following the closure of the Festspielhaus during the Second World War, the 1950s saw productions by Wagner's grandsons Wieland and Wolfgang Wagner (known as the 'New Bayreuth' style), which emphasised the human aspects of the drama in a more abstract setting.[12]

Perhaps the most famous modern production was the centennial production of 1976, the Jahrhundertring, directed by Patrice Chéreau and conducted by Pierre Boulez.[13] Set in the industrial revolution, it replaced the depths of the Rhine with a hydroelectric power dam and featured grimy sets populated by men and gods in 19th and 20th century business suits. This drew heavily on the reading of the Ring as a revolutionary drama and critique of the modern world, famously expounded by George Bernard Shaw in The Perfect Wagnerite. Early performances were booed but the audience of 1980 gave it a 90-minute ovation in its final year; the production is now generally regarded as revolutionary and a classic.

Although many Ring productions try to remain close to Wagner's original stage design and direction, others seek to re-interpret the Ring for modern audiences, often including decor and action that Wagner himself did not envisage. The production by Peter Hall, conducted by Georg Solti at Bayreuth in 1983 is an example of the former, while the production by Richard Jones at the Royal Opera House Covent Garden in 1994–1996, conducted by Bernard Haitink, is an example of the latter.

In 2003 the first production of the cycle in Russia in modern times was conducted by Valery Gergiev at the Mariinsky Opera, Saint Petersburg, designed by George Tsypin. The production drew parallels with Ossetian mythology.[14]

The Royal Danish Opera performed a complete Ring cycle in May 2006 in its new waterfront home, the Copenhagen Opera House. This version of the Ring tells the story from the viewpoint of Brünnhilde and has a distinct feminist angle. For example, in a key scene in Die Walküre, it is Sieglinde and not Siegmund who manages to pull the sword Nothung out of a tree. At the end of the cycle, Brünnhilde does not die, but instead gives birth to Siegfried's child.[15]

San Francisco Opera and Washington National Opera began a coproduction of a new Ring cycle in 2006 directed by Francesca Zambello. The production uses imagery from various eras of American history and has a feminist and environmentalist viewpoint.

The Metropolitan Opera began a new Ring cycle in 2010, conducted by James Levine with Bryn Terfel as Wotan. Deborah Voigt was Brünnhilde in the April 2011 production of Die Walküre. The staging of Das Rheingold by Robert Lepage involved 24 identical wedges able to rotate independently on a horizontal axis across the stage, providing level, sloping, angled or moving surfaces facing the audience. Bubbles, falling stones and fire are projected on to these surfaces, linked by computer with the music and movement of the characters. In 2013, The Met's orchestra and chorus were awarded the Grammy Award for Best Opera Recording for their performance of Der Ring des Nibelungen.[16]

It is possible to perform The Ring with fewer resources than usual. In 1990, the City of Birmingham Touring Opera (now Birmingham Opera Company), presented a two-evening adaptation (by Jonathan Dove) for a limited number of solo singers, each doubling several roles, and 18 orchestral players.[17] This version was subsequently given productions in the USA.[18] A heavily cut-down version (7 hours plus intervals) was performed at the Teatro Colón in Buenos Aires on 26 November 2012 to mark the 200th anniversary of Wagner's birth.[citation needed]

Recordings of the Ring cycle

Main article: Der Ring des Nibelungen discography

Other treatments of the Ring cycle

Orchestral "versions" of the Ring Cycle, summarizing the work in a single movement of an hour or so, have been made by Leopold Stokowski, Lorin Maazel (Der Ring ohne Worte) (1988) and Henk de Vlieger (The Ring: an Orchestral Adventure), (1991).[19]

The comedienne Anna Russell had a renowned 22-minute routine "explaining" the plot and music of the Ring cycle, which included a phrase which became identified with her: "I'm not making this up, you know."

Produced by the Ridiculous Theatrical Company, Charles Ludlam's 1977 play Der Ring Gott Farblonjet was a spoof of Wagner's operas. The show received a well-reviewed 1990 revival in New York at the Lucille Lortel Theater.[20]

In 1982 the National Theatre of Brent performed a summary of the cycle in about 75 minutes, which also included a recapitulation of the composer's life, with a cast of three and a piano (inviting members of the audience to participate as Valkyries and as Gunther's vassals).

Tom Holt's 1982 humorous fantasy novel, Expecting Someone Taller, includes many of the characters of Wagner's operas, and features the Ring and the Tarnhelm. Stephen R. Donaldson's science-fiction space opera series The Gap Cycle also shares elements with Der Ring des Nibelungen.

The protagonist in Jonathan Tolins' play The Twilight of the Golds (1993) is obsessed with the Ring cycle, and tries to show his family how its themes relates to their conflict. The film was adapted into a feature film in 1996.

What's Opera, Doc? is a 1957 American animated cartoon short in the Merrie Melodies series, directed by Chuck Jones for Warner Bros. Cartoons. The Michael Maltese story features Elmer Fudd chasing Bugs Bunny through a parody Richard Wagner's operas, particularly Der Ring des Nibelungen and Tannhäuser. It is sometimes characterized as a condensed version of Wagner's Ring cycle, and its music borrows heavily from the second opera Die Walküre, woven around the standard Bugs–Elmer conflict.

Wagner's Ring and Tolkien's Ring

J. R. R. Tolkien's fantasy novel The Lord of the Rings (1937–49) shares elements with Der Ring des Nibelungen, but Tolkien himself denied that he had been inspired by Wagner's work, saying that "Both rings were round, and there the resemblance ceases."[21] Many similarities can be explained because Tolkien and Wagner both drew upon the same source material, including the Völsunga saga and the Poetic Edda. But scholar Edward Haymes suggests that Tolkien owes a direct debt to Wagner's cycle for concepts like a ring that gives its owner mastery of the world, and that works to corrupt the minds and wills of its possessors.[22][23] There are various similarities, Sméagol's murder of his cousin Deagol for the ring reflects Fafnir's murder of Fasolt.




  • Burbidge, Peter and Richard Sutton, The Wagner Companion, London, 1979. ISBN 0-571-11450-4
  • ISBN 0-19-315318-1.
  • Di Gaetani, John Louis, Penetrating Wagner's Ring: An Anthology. New York: Da Capo Press, 1978. ISBN 978-0-306-80437-3
  • Gregor-Dellin, Martin, (1983) Richard Wagner: His Life, His Work, His Century. Harcourt, ISBN 0-15-177151-0
  • Grey, Thomas S. (ed.) (2008) The Cambridge Companion to Wagner, Cambridge University Press. ISBN 978-0-521-64439-6
  • Holman, J.K. Wagner's Ring: A Listener's Companion and Concordance. Portland OR: Amadeus Press, 2001.
  • Lee, M. Owen, (1994) Wagner's Ring: Turning the Sky Round. Amadeus Press, ISBN 978-0-87910-186-2
  • Magee, Bryan, (2001) The Tristan chord: Wagner and Philosophy. Metropolitan Books, ISBN 0-8050-6788-4
  • Magee, Bryan, (1988) Aspects of Wagner. Oxford University Press, ISBN 0-19-284012-6
  • May, Thomas, (2004) Decoding Wagner. Amadeus Press, ISBN 978-1-57467-097-4
  • Mendelssohn, Fanny, ed. Marcia Citron (1987) Letters of Fanny Hensel to Felix Mendelssohn. Pendragon Press ISBN 978-0-918728-52-4
  • Millington, Barry (editor) (2001) The Wagner Compendium. Thames and Hudson, ISBN 0-500-28274-9
  • Millington, Barry (2008) Der Ring des Nibelungen: conception and interpretation in Grey (2008), 74–84
  • Sabor, Rudolph, (1997) Richard Wagner: Der Ring des Nibelungen: a companion volume. Phaidon Press, ISBN 0-7148-3650-8
  • accessed 20 July 2010.
  • Spotts, Frederick, (1999) ISBN 0-7126-5277-9
  • Wagner, Richard, tr. William Ashton Ellis (1994), The Art Work of the Future, and other works, Lincoln and London. ISBN 978-0-8032-9752-4. "A Communication to My Friends" is on pp. 269–392.

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