A composition for three string instruments. The term is generally used to refer to works from the Classical period to the present, scored either for two violins and cello or for violin, viola and cello; many Renaissance consort pieces and Baroque sonatas, however, were also written for three string instruments, either viols or violins, with or without continuo (see Sonata, §I).
The trio for two violins and cello was an outgrowth of the Baroque trio sonata, and many such works in the mid-18th century bore the title ‘sonata’, including trios by J.G. Schwanenberger, J.F. Reichardt and C.A. Campioni (Six Sonatas or Trio’s, c1764). There was a tendency at this time, as in much pre-Classical music, towards a texture in which the two violins were treated on more or less equal terms while the bass was used to provide harmonic support and a pulsating rhythm. In some cases (Campioni’s sonatas and Pugnani’s op.1, 1754) the bass part was still figured for keyboard continuo. In Schwanenberger’s sonatas and in trios by Fils, Haydn, J.C. and C.P.E. Bach, Boccherini and Dittersdorf, it is impossible to be certain whether or not a continuo instrument was still envisaged by the composer, although in the later examples by Boccherini this is most unlikely.
Johann Stamitz's Six sonates à trois ou avec tout l'orchestre op.1 (Paris, c1755) and similarly described works by Cannabich op.3 (1766), Mysliveček (London, 1768) and, with optional horn parts, Gossec op.9 (1766) are characteristic of a genre precariously balanced between orchestral and true chamber music, in which orchestral performance was either permissible or actually called for. (A similar flexibility in the medium of performance is found in the early history of the string quartet.)
During the 1770s and 1780s both the use of continuo and the possibility of orchestral performance were gradually dropped. Although the trio for two violins and cello was not wholly abandoned even during the 19th century, that for violin, viola and cello began to take precedence. Haydn seems to have been the first to use this combination, soon followed by Simon Le Duc (op.1, 1768), Boccherini (op.14, 1772) and Giardini (opp.17 and 20). The 1770s also saw the development, stemming largely from Paris, of the trio concertant (see Quatuor concertant), a genre which persisted to the close of the century, in which the three instruments were treated with equality in an obbligato fashion in a comparatively rich and elaborate texture. Cambini’s opp.1 and 2 are typical, although the former retains the somewhat old-fashioned instrumentation of two violins and cello.
The earlier Classical trio often adopted a three-movement plan. Haydn's preference is for an initial Adagio or Allegro and an extended minuet placed second or third. Four-movement schemes, however, are not unusual in Boccherini's later trios, and five or six movements are commonly found in divertimentos. The highpoint of the string trio repertory is Mozart’s Divertimento for violin, viola and cello k563, a trio concertant in six movements. Beethoven’s early string trios exemplify both types: op.3 is closely modelled on Mozart’s Divertimento, while the three trios of op.9 belong to the four-movement category. Mozart’s fine introductions to his arrangements of fugues by J.S. and W.F. Bach and the two trios by Schubert complete the most valuable part of the Viennese repertory.
The term ‘Grand Trio’ was used at the beginning of the 19th century to distinguish full-scale and technically advanced compositions from those of slighter proportions often intended for amateurs or students. The trio brillant (e.g. Rodolphe Kreutzer’s op.16, c1800) represents another category in which one instrument is treated in a soloistic fashion with brilliant passage-work, double stops and sometimes cadenzas, while the others provide little more than an accompaniment. Such trios often consisted of or incorporated variations on fashionable operatic airs. The violin was not invariably the concertante instrument: B.H. Romberg’s op.38 is for concertante cello with a viola and a second cello.
The slender nature of the medium seems to have been unattractive to late 19th-century composers. There are trios by Reger and Brahms’s friend Heinrich von Herzogenberg; but the most rewarding is Dvořák’s Terzetto for two violins and viola, a rather unusual combination which, however, had been used previously in the Six trios (1764) of J.C. Bach and later by Cambini, and was revived subsequently by Kodály, Martinů and Henk Badings.
During the 20th century a leaning towards clear-textured media led to a marked revival of the string trio. Important contributions include two trios in neo-classical style by Hindemith (1924, 1935); two that employ 12-note serial techniques – Webern's two-movement Trio op.20 (1926–7) and Schoenberg's single-movement Trio op.45 (1946), a major landmark in the repertory (apparently prompted by his near-fatal heart attack in August of the same year); and some finely sculpted works by Dohnányi (Serenade, 1904), Willy Burkhard (1929), Jean Françaix (1933), Frank Martin (1936), Albert Roussel (1937), Ernst Krenek (his elegantly titled Parvula corona musicalis ad honorem J.S. Bach, 1950) and Wolfgang Fortner (1952). More recent examples include a Trio for two violins and cello (1984) by Wilhelm Killmayer, Alfred Schnittke's String Trio (1985), a two-movement work, classically designed but with exacting modernist textures, which was written to mark the centenary of Alban Berg's birth, and works, similarly for the standard combination, by Aribert Reimann (1987) and Annette Schlünz (1989).
W. Altmann: ‘Beethovens Umarbeitung seines Streichtrios Op.3 zu einem Klaviertrio’, ZfM, iii (1920–21), 124–58
H. Strobel: ‘Neue Kammermusik von Paul Hindemith’, Melos, iv (1925), 542–8
T. Adorno: ‘Kammermusik von Paul Hindemith’, Die Musik, xix/1 (1926), 24–8
E. Leuchter: Die Kammermusikwerke Fl. L. Gassmans (diss., U. of Vienna, 1926)
C. Engel: ‘Beethoven’s Opus 3 – An “Envoi de Vienne”?’, MQ, xiii (1927), 261–79
E. Stein: ‘Weberns Trio op.20’, Neue Musikzeitung, xlix (1928), 517–19
A. Einstein: ‘Mozart’s Four String Trio Preludes to Fugues of Bach’, MT, lxxvii (1936), 209–16
R.S. Hill: ‘Arnold Schoenberg: String Trio’, Notes, viii (1950), 127–9
W. Hymanson: ‘Schoenberg’s String Trio (1946)’, MR, xi (1950), 184–94
C. Mason: ‘Webern's Later Chamber Music’, ML, xxxviii (1970), 232–7
E.R. Meyer: : Florian Gassmann and the Viennese Divertimento (diss., U. of Pennsylvania, 1963)
E. Platen: ‘Beethoven’s Streichtrio D–Dur, opus 9 nr.2: zum Problem der thematischen Einheit mehrsätziger Formen’, Colloquium amicorum: Joseph Schmidt-Görg zum 70. Geburtstag (Bonn, 1967), 260–82
H. Unverricht: Geschichte des Streichtrios (Tutzing, 1969) [incl. bibliography]
J.M. Peel: ‘On Some Celebrated Measures of the Schoenberg Trio’, PNM, xiv/2, xv/1 (1976), 260–79
D.E.J. Keaney: The Genoa Manuscripts: Recently discovered Trios of Johann Christian Bach (diss., U. of Texas, 1977)
B.S. Brook: ‘Haydn's String Trios: a Misunderstood Genre’, CMc, no.36 (1983), 61–77
MICHAEL TILMOUTH/BASIL SMALLMAN