|Component intervals from root|
|augmented fourth (tritone)|
|Forte number or Tuning|
The Tristan chord is a chord made up of the notes F, B, D♯ and G♯. More generally, it can be any chord that consists of these same intervals: augmented fourth, augmented sixth, and augmented ninth above a root. It is so named as it is heard in the opening phrase of Richard Wagner's opera Tristan und Isolde as part of the leitmotif relating to Tristan.
The notes of the Tristan chord are not unusual; they could be re-spelled to form a conventional half-diminished seventh chord. What distinguishes the chord is its unusual relationship to the implied key of its surroundings. When Tristan und Isolde was first heard in 1865, the chord was considered innovative, disorienting, and daring. Musicians of the twentieth century often identify the chord as a starting point for the modernist disintegration of tonality.
This motif also appears in measures 6, 10, and 12, several times later in the work and at the end of the last act.
Much has been written about the Tristan chord's possible harmonic functions or voice leading (melodic function), and the motif has been interpreted in various ways. For instance, Schering (1935) traces the development of the Tristan chord through ten intermediate steps, beginning with the Phrygian cadence (iv6-V).
Vogel points out the "chord" in earlier works by Guillaume de Machaut, Carlo Gesualdo, Bach, Mozart, Beethoven, or Louis Spohr, as in the following example from Beethoven's Piano Sonata No. 18, tempo allegro:
What makes the Tristan motif different from earlier appearances of the same notes, in the eyes of many analysts, is its duration. In the Beethoven example, the E♭ resolves to D in approximately a quarter of the time it takes the G♯ to "resolve" to the A in the Wagner. In Wagner, the resolution is used merely in passing to a further chromatic dissonance (the A♯ in the following measure), rather than as a resting point in itself. In Beethoven, the notes' simultaneity may be considered to consist partly of nonchord tones; it is not a chord or harmonic entity in itself.
The Tristan chord's significance is in its move away from traditional tonal harmony, and even towards atonality. With this chord, Wagner actually provoked the sound or structure of musical harmony to become more predominant than its function, a notion which was soon explored by Debussy and others. In the words of Robert Erickson, "The Tristan chord is, among other things, an identifiable sound, an entity beyond its functional qualities in a tonal organization."
Although at the same time enharmonically sounding like the half-diminished chord F-A♭-C♭-E♭, it can also be interpreted as the suspended altered subdominant II: B-D♯-F-G♯ (the G♯ being the suspension in the key of A minor).
Jean-Jacques Nattiez writes that musical analyses are determined by analytical situations especially in regard to the tripartition, plots, and transcendent principles. Regarding the Tristan chord, the situations discussed here include what the analyst believes happens with the chord later in Tristan and Isolde, and relate to the possible belief in only three harmonic functions, or in functional successions determined by the circle of fifths.
According to J. Chailley (1963, p. 40), "it is rooted in a simple dominant chord of A minor [E major], which includes two appoggiaturas resolved in the normal way":
Thus in this view it is not a chord but an anticipation of the dominant chord in measure three. He explains (1963, p. 8): "Tristan's chromaticism, grounded in appoggiaturas and passing notes, technically and spiritually represents an apogee of tension. I have never been able to understand how the preposterous idea that Tristan could be made the prototype of an atonality grounded in destruction of all tension could possibly have gained credence. This was an idea that was disseminated under the (hardly disinterested) authority of Schoenberg, to the point where Alban Berg could cite the Tristan Chord in the Lyric Suite, as a kind of homage to a precursor of atonality. This curious conception could not have been made except as the consequence of a destruction of normal analytical reflexes leading to an artificial isolation of an aggregate in part made up of foreign notes, and to consider it—an abstraction out of context—as an organic whole. After this, it becomes easy to convince naive readers that such an aggregation escapes classification in terms of harmony textbooks."
Nattiez distinguishes between functional and nonfunctional analyses of the chord.
Functional analyses 
Functional analyses include interpreting the chord's root as on:
- the fourth scale degree (IV) of A minor (D, according to Arend "a modified minor seventh chord" F-B-D♯-G♯ → F-C♭-E♭-A♭ → F-B-D-A = D-F-A, according to Lorenz an augmented sixth chord F-A-D♯) (Arend, Riemann, D'Indy, Lorenz, Deliège, Gut), based after Riemann on the transcendent principle that there are only three functions, tonic, subdominant, and dominant (I, IV, and V);
- the second degree (II) of A minor (B) (Piston, Walter 1941, Goldman 1965) (Schoenberg, Arnold, 1954), as a French sixth (F-A-B-D♯), based on the transcendent principle of closeness on the circle of fifths with IV being farther than II, with G♯ seen as an accented passing tone, or
- as a secondary dominant (V/V=B, five of five, I=A, V=E), and thus also with a root on B (Ergo 1921, Kurth 1920, Distler 1940), favoring the fifth motion B to E and seeing the chord as a seventh chord with lowered fifth (B-D♯(D♮)-F♯-A).
- F or B in A: Considering the G♯ as an appoggiatura, the chord can be interpreted as a type of augmented sixth, specifically the French sixth (F A B D♯ = F B D♯ (G♯-)A).
D'Indy (1903, p. 117), who analyses the chord as on IV after Riemann's transcendent principle (as phrased by Serge Gut: "the most classic succession in the world: Tonic, Subdominant, Dominant" (1981, p. 150)) and rejects the idea of an added "lowered seventh", eliminates, "all artificial, dissonant notes, arising solely from the melodic motion of the voices, and therefore foreign to the chord," finding that the Tristan chord is "no more than a subdominant in the key of A, collapsed in upon itself melodically, the harmonic progression represented thus:
"This is the simplest in the world," just a sophisticated sixth chord.
Deliège, independently, sees the G♯ as an appoggiatura to A, describing that
in the end only one resolution is acceptable, one that takes the subdominant degree as the root of the chord, which gives us, as far as tonal logic is concerned, the most plausible interpretation ... this interpretation of the chord is confirmed by its subsequent appearances in the Prelude's first period: the IV6 chord remains constant; notes foreign to that chord vary.—1979, p.23
Nonfunctional analyses 
Nonfunctional analyses are based on structure (rather than function), and are characterized as vertical characterizations or linear analyses. Vertical characterizations include interpreting the chord's root as on the
- seventh degree (VII) (Ward 1970, Sadai 1980), of F♯ minor (E♯) (Kistler 1879, Jadassohn 1899)
Linear analyses include that of Noske (1981: 116-17) and Schenker was the first to analyse the motif entirely through melodic concerns. Schenker and later Mitchell compare the Tristan chord to a dissonant contrapuntal gesture from the E minor fugue of The Well-Tempered Clavier, Book I (cf. Schenker 1925-1930 II: 29).
William Mitchell, from a Schenkerian perspective, does not see the G♯ as an appoggiatura because the melodic line (oboe: G♯-A-A♯-B) ascends to B, making the A a passing note. This ascent by minor third is mirrored by the descending line (cello: F-E-D♯, English horn: D), a descent by minor third, making the D♯, like A♯, an appoggiatura. This makes the chord a diminished seventh (G♯-B-D-F).
Serge Gut (1981, p. 150), argues that, "if one focuses essentially on melodic motion, one sees how its dynamic force creates a sense of an appoggiatura each time, that is, at the beginning of each measure, creating a mood both feverish and tense ... thus in the soprano motif, the G♯ and the A♯ are heard as appoggiaturas, as the F and D♯ in the initial motif." The chord is thus a minor chord with added sixth (D-F-A-B) on the fourth degree (IV), though it is engendered by melodic waves.
Allen Forte, who (1988, p. 328) identifies the chord as an atonal set, 4-27 (half-diminished seventh chord) but then "elect[s] to place that consideration in a secondary, even tertiary position compared to the most dynamic aspect of the opening music, which is clearly the large-scale ascending motion that develops in the upper voice, in its entirety a linear projection of the Tristan Chord transposed to level three, g♯'-b'-d"-f♯"."
Schoenberg (1911, p. 284) describes it as a "wandering chord [vagierender Akkord]... it can come from anywhere."
Mayrberger's opinion 
After summarizing the above analyses Nattiez asserts that the context of the Tristan chord is A minor, and that analyses which say the key is E or E♭ are "wrong". He privileges analyses of the chord as on the second degree (II). He then supplies a Wagner-approved analysis, that of Czech professor K. Mayrberger (1878), who "places the chord on the second degree, and interprets the G♯ as an appoggiatura. But above all, Mayrberger considers the attraction between the E and the real bass F to be paramount, and calls the Tristan chord a Zwitterakkord (a bisexual or androgynous chord), whose F is controlled by the key of A minor, and D♯ by the key of E minor." According to Hans von Wolzogen, Wagner, "with considerable delight believed he had found in this heretofore unknown man from faraway Hungary the theorist he had long been waiting for."
Responses and influences 
The chord and the figure surrounding it is well enough known to have been parodied and quoted by a number of later musicians. Berg also quotes it in his Lyric Suite for string quartet, deriving the figure from his twelve-tone compositional material. Arthur Sullivan uses the chord (re-spelling it as a chord of F seventh with a flattened fifth) during a recitative in his operetta H.M.S. Pinafore, and Debussy includes the chord in a setting of the phrase 'je suis triste' in his opera Pelléas et Mélisande. Debussy also jokily quotes the opening bars of Wagner's opera several times in "Golliwogg's Cakewalk" from his piano suite Children's Corner. Benjamin Britten slyly invokes it at the moment in Albert Herring when Sid and Nancy spike Albert's lemonade and then again when he drinks it. More recently, American composer and humorist Peter Schickele crafted a tango around this same figure, a chamber work for four bassoons entitled Last Tango in Bayreuth.
The Brazilian conductor and composer Flavio Chamis wrote Tristan Blues, a composition based on the Tristan chord. The work, for harmonica and piano was recorded on the CD "Especiaria" , released in Brazil by the Biscoito Fino label. Flavio Chamis found an intriguing relation between the Tristan chord/resolution and the blues scale - much used in jazz - in which all have practically the same notes.
In 1993, the opening theme was used in the film Thirty Two Short Films About Glenn Gould in the scene on Lake Simcoe as performed by the NBC Philharmonic Orchestra, conducted by Arturo Toscanini (recorded 1952). Gould had been a fan of Wagner and adapted some of his music to piano, one of Gould's rare recordings from the Romantic Period.
See also 
- Schering, Arnold (1935). "Musikalische Symbolkunde", Jahrbuch der Musikbibliothek, pp 15-36.
- Vogel, Martin (1962). Der Tristan-Akkord und die Krise der modernen Harmonielehre, p. 12. Titled in response to Kurth (1920). Cited in Nattiez (1990).
- Erickson, Robert (1975). Sound Structure in Music. Oakland, California: University of California Press. p. 18. ISBN 0-520-02376-5.
- Chailley, J. (1963). "Tristan et Isolde de Richard Wagner", Paris: Centre de documentation universitaire. Discussed Diény (1965) and Serge Gut (1981: 149). Cited in Nattiez (1990).
- Nattiez, Jean-Jacques (1990) . Music and Discourse: Toward a Semiology of Music (Musicologie générale et sémiologue). Translated by Carolyn Abbate (1990). Princeton, N.J.: Princeton University Press. pp. 219–29. ISBN 0-691-02714-5.
- Benward & Saker (2008). Music in Theory and Practie, Vol. II, p.233. ISBN 978-0-07-310188-0.
- Schoenberg, Arnold: "Structural Functions of Harmony" (Revised Edition), pg. 77, W. W. Norton & Company, 1969, Library of Congress - 74-81181
- Ellis, Mark (2010). A Chord in Time: The Evolution of the Augmented Sixth from Monteverdi to Mahler, pp. 29-32 and pp. 211-214. Farnham: Ashgate. ISBN 978-0-7546-6385-0.
- D'Indy, V. (1903). Cours de composition musicale, vol. 1. Paris: Durand. Cited in Nattiez (1990), p.224.
Further reading 
- Bailey, Robert (1986). Prelude and Transfiguration from Tristan and Isolde (Norton Critical Scores). ISBN 0-393-95405-6. Contains complete orchestral score, together with extensive discussion of the Prelude (especially the chord), Wagner's sketches, and leading essays by various analysts.
- Kurth, Ernest (1920). Romantische Harmonik und ihre Krise in Wagners "Tristan".
- Magee, Bryan (2002). The Tristan Chord: Wagner and Philosophy. ISBN 0-8050-7189-X.
- Nattiez, Jean-Jacques (1990). Wagner androgyne. ISBN 2-267-00707-X. Contains discussion of the Tristan chord as "androgynous". 1997 English edition (trans. Stewart Spencer) ISBN 0-691-04832-0.