Monothematic expositions It is not necessarily the case that the move to the dominant key in the exposition is marked by a new theme. Haydn in particular was fond of using the opening theme, often in a truncated or otherwise altered form, to announce the move to the dominant, as in the first movement of his
Sonata Hob. XVI/49 in E major. Mozart also occasionally wrote such expositions: for instance in the
Piano Sonata K. 570 or the
String Quintet K. 593. Such expositions are often called
monothematic, meaning that one theme serves to establish the opposition between tonic and dominant keys. This term is misleading, since most "monothematic" works have multiple themes: most works so labeled have additional themes in the second subject group. Rarely, as in the fourth movement of Haydn's
String Quartet in B major, Op. 50, No. 1, did composers perform the
tour de force of writing a complete sonata exposition with just one theme. A more recent example is
Edmund Rubbra's Symphony No. 2. The fact that so-called monothematic expositions usually have additional themes is used by Charles Rosen to illustrate his theory that the Classical sonata form's crucial element is some sort of
dramatization of the arrival of the dominant. Using a new theme was a very common way to achieve this, but other resources such as changes in texture, salient cadences and so on were also accepted practice.
No transitions between the first and second subject groups In some sonata-form works, especially in the Classical period, there is no transitional material linking the subject groups. Instead, the piece moves straight from the first subject group to the second subject group via
common-tone modulation. This happens in the first movement of Mozart's
Symphony No. 31 and again in the third movement of his
Symphony No. 34. It also occurs in the first movement of Beethoven's
Symphony No. 1. In the exposition, the first subject group ends on a half-cadence in tonic, and the second subject group immediately follows in the dominant key (without a transition).
Expositions that modulate to other keys The key of the second subject may be something other than the dominant (for a major-mode sonata movement) or relative major (for a minor-key movement). A second option for minor-mode sonata form movements was to modulate to the minor dominant; this option, however, robs the sonata structure of the space of relief and comfort that a major-mode second theme would bring, and was therefore used primarily for a bleak, grim effect, as Beethoven did with some frequency.
Mendelssohn also did this in the first movement of his
Symphony No. 3 and the last movement of his
Symphony No. 4. A minor-key sonata form movement can also modulate to the major dominant, as in the first movements of
Tchaikovsky's
Symphony No. 1 and
Brahms's
Symphony No. 4. About halfway through his career, Beethoven also began to experiment with other tonal relationships between the tonic and the second subject group. The most common practice, for Beethoven and many other composers from the Romantic era, was to use the
mediant or
submediant, rather than the dominant, for the second group. For instance, the first movement of the
"Waldstein" sonata, in
C major, modulates to the mediant
E major, while the opening movement of the
"Hammerklavier" sonata, in
B major, modulates to the submediant
G major, and
String Quartet No. 13 in the same key modulating to the flattened
submediant key of
G major. Tchaikovsky also implemented this practice in the last movement of his
Symphony No. 2; the movement is in
C major and modulates to the flattened submediant
A major. The young Chopin even experimented with expositions that do not modulate at all, in the opening movements of his
Piano Sonata No. 1 (remaining in C minor throughout) and his
Piano Concerto No. 1 (moving from E minor to E major). Beethoven began also to use the submediant major with more frequency in minor-key sonata-form movements, as in the first movements of
Symphony No. 9,
Piano Sonata No. 32, and String Quartets
No. 11 and
No. 15. The latter case transposes the second repeat of its exposition by a fifth, starting on the minor dominant (instead of the tonic) and finishing on the major mediant (instead of the submediant). The first movement of
Richard Strauss's
Symphony No. 2, in
F minor, modulates to the submediant
D major, as do the F minor first movements of Brahms'
first clarinet sonata and
piano quintet; all three works balance this downward third by moving up to the major mediant (
A major) for the key of the second movement. Rarely, a major-mode sonata form movement will modulate to a minor key for the second subject area, such as the mediant minor (Beethoven Sonata Op. 31/1, i), the relative minor (first movements of Beethoven Triple Concerto and Brahms Piano Trio No. 1) or even the minor dominant (Brahms Piano Concerto No. 2, i). In such cases, the second theme will often return initially in the tonic minor in the recapitulation, with the major mode restored later on. During the late Romantic period, it was also possible to modulate to remote tonal areas to represent divisions of the octave. In the first movement of Tchaikovsky's
Symphony No. 4, the first subject group is in the tonic
F minor but modulates to
G minor and then to
B major for the second subject group. The recapitulation begins in
D minor and modulates to
F major, and goes back to the parallel
F minor for the coda. , who is known for using
three-key expositions Expositions with more than two key areas The exposition need not only have two key areas. Some composers, most notably
Schubert, composed sonata forms with three or more key areas (see
three-key exposition). The first movement of Schubert's
Quartet in D minor, D. 810 ("Death and the Maiden"), for example, has three separate key and thematic areas, in D minor, F major, and A minor. Similarly,
Chopin's
Piano Concerto in F minor uses F minor, A major, and C minor in its first movement's exposition. In both cases, the transition is i–III–v, an elaboration of the minor schema of either using i–III or i–v. This is by no means the only scheme, however: the opening movement of Schubert's Violin Sonata in G minor, D. 408, uses the scheme i–III–VI, and the opening movement of Schubert's
Symphony No. 2 in B major, D. 125, uses the scheme I–IV–V. The first movement of Tchaikovsky's
Symphony No. 5 uses the scheme i–v–VII. An extreme example is the finale to Schubert's
Symphony No. 6, D. 589, which has a six-key exposition (C major, A major, F major, A major, E, and G major), with a new theme for each key. The second subject group can start in a particular key and then modulate to that key's parallel major or minor. In the first movement of Brahms'
Symphony No. 1 (in C minor), the second subject group begins in the relative E major and goes to the parallel mediant
E minor. It also occurs in the first movement of
Beethoven's
Piano Sonata No. 8 (also in C minor), except the second subject group starts in E minor before going to E major. The opening movement of Dvorak's
Symphony No. 9 in E minor has its second subject group start in the minor mediant G minor and then to its parallel G major. And in the opening movement of his
Symphony No. 6 in D major, the first theme of the second subject group is in the relative
B minor while the second theme is in the parallel submediant
B major.
Modulations within the first subject group The first subject group need not be entirely in the tonic key. In the more complex sonata expositions there can be brief modulations to fairly remote keys, followed by reassertion of the tonic. For example, Mozart's
String Quintet in C, K. 515, visits C minor and D major as chromaticism within the C major first subject group, before finally moving to D major, the dominant of the dominant major (G major), preparing the second subject group in the dominant. Many works by Schubert and later composers utilized even further harmonic convolutions. In the first subject group of Schubert's Piano Sonata in B, D. 960, for example, the theme is presented three times, in B major, in G major, and then again in B major. The second subject group is even more wide-ranging. It begins in F minor, moves into A major, then through B major to F major.
Recapitulations in the "wrong key" In the recapitulation section, the key of the first subject group may be in a key other than tonic, most often in the subdominant, known as a "subdominant recapitulation". In some pieces by Mozart, such as Mozart's
Piano Sonata No. 16 in C, K. 545, or the finale of his
String Quartet No. 14 in G, K. 387, the first subject group will be in the subdominant and then modulate back to tonic for the second subject group and coda. This case is also found in the first movement of Beethoven's
"Kreutzer" sonata. Schubert was also a prominent user of the subdominant recapitulation; it appears for example in the opening movements of his
Symphonies No. 2 and
No. 5, as well as those of his piano sonatas
D 279,
D 459,
D 537,
D 575, as well as the finale of
D 664. Sometimes this effect is also used for false reprises in the "wrong key" that are soon followed by the actual recapitulation in the tonic, such as in the first movement of Haydn's
quartet Op. 76 No. 1 in G (false reprise in the subdominant), or the finale of Schubert's
piano sonata in A, D 959 (false reprise in the major submediant). A special case is the recapitulation that begins in the tonic minor, for example in the
slow movement of Haydn's quartet Op. 76 No. 4 in E, or the opening movement of Haydn's
Symphony No. 47 in G major. In the Classical period, the subdominant is the only possible substitute for the tonic at this position (because any other key would need resolution and would have to be introduced as a false reprise in the development), but with the erosion of the distinction between the sharp and flat directions and the blurring of tonal areas true recapitulations beginning in other keys became possible after around 1825. It is possible for the first subject group to begin in tonic (or a key other than tonic), modulate to another key and then back to tonic for the second subject group. In the finale of the original 1872 version of Tchaikovsky's
Symphony No. 2, the first subject group begins in the tonic
C major, modulates to
E major, then through
E major, and then modulates back to tonic for the second subject group and coda. And in the last movement of Schubert's
Symphony No. 9 in C major, the first subject group is in the flattened mediant E major, modulates to the subdominant
F major and then back to tonic for the second subject group and coda. It is also possible to have the second subject group in a key other than tonic while the first subject group is in the home key. For instance in the first movement of
Richard Strauss's
Symphony No. 2 in
F minor, the recapitulation begins with the first subject group in tonic but modulates to the mediant
A major for the second subject group before modulating back to F minor for the coda. Another example is the first movement of
Dvorak's
Symphony No. 9. The recapitulation begins in the tonic E minor for the first subject group, but the second subject group modulates to G-sharp minor, then through A-flat major before modulating back to the tonic key for the coda. Similarly, in Beethoven's
"Waldstein" Sonata, the first subject group is in the tonic C major, then modulates to A major for the first part of the second subject group but quickly goes through A minor to modulate back to tonic for the rest of the second subject group and coda. Another possibility is both subject groups in the recapitulation going through multiple keys. In the first movement of Schubert's
Symphony No. 8, the first subject group begins in the tonic B minor but modulates to E minor and then to F minor. The second subject group starts in the mediant D major before modulating to the parallel tonic B major. Romantic works even exhibit
progressive tonality in sonata form: for example, the second movement 'Quasi-Faust' from
Charles-Valentin Alkan's ''
Grande sonate 'Les quatre âges''' is in D minor, and while the exposition travels from D to the major subdominant G major, the recapitulation begins again in D minor and ends in the relative major F major, and stays there till the end of the movement. Such a scheme may have been constructed to conform with the programmatic nature of the movement, but also fits well with the Romantic penchant for beginning a work at maximum tension and decreasing the tension afterwards, so that the point of ultimate stability is not reached until the last possible moment. (Furthermore, the identification of a minor key with its relative major is common in the Romantic period, supplanting the earlier Classical identification of a minor key with its parallel major.)
Partial or varied recapitulations In some pieces in sonata form, in the recapitulation, the first subject group is omitted, leaving only the second subject group, like the second movement of
Haydn's Sonata Hob. XVI/35, as well as the opening movements of Chopin's
Piano Sonata No. 2 and
No. 3. It is also possible for the first subject group to be slightly different in comparison of the exposition, like the fourth movement of
Dvorak's
Symphony No. 9. Another example occurs in the finale of Mozart's string quartet
K. 387, where the opening of the first subject group is cut, and in the
quintet K. 515, where a later portion of the first subject group is cut. On the other hand, it is also possible for the subject groups to be reversed in order, like the fourth movement of
Bruckner's
Symphony No. 7, or the first movement of Mozart's
piano sonata in D major, K. 311. The second subject group's melody can be different compared to the exposition, like
Haydn's
Symphony No. 44. Such melodic adjustment is common in minor-key sonata forms, when the mode of the second subject needs to be changed, for example in the opening movement of Mozart's wind serenade
K. 388. In rare cases, the second subject theme can be omitted, as in the finales of Tchaikovsky's
Symphony. No 1 and his
Violin Concerto in D major; in the case of the first symphony, the movement's introductory theme replaces the second subject group.
Truncated sonata form Occasionally, especially in some Romantic works, the sonata form extends only as far as the end of the exposition, at which point the piece transitions directly into the next movement instead of a development section. One example is
Henryk Wieniawski's
Violin Concerto No. 2 in D minor. Another example is
Fritz Seitz's Violin Concertos for students, where such a truncated sonata form is used ostensibly to cut down on the first movements' length. Sometimes, the third movement of such works is the recapitulation of the first movement (one example being Franz Strauss' Horn Concerto in C Minor), making the entire work effectively a single-movement sonata. Some Classical slow movements involve a different sort of truncation, in which the development section is replaced altogether by a short retransition. This occurs in the slow movements of Mozart's quartets
K. 387,
K. 458,
K. 465,
K. 575, and
K. 589. It is also common in overtures, occurring for example in Mozart's overture to
Le nozze di Figaro, or Rossini's overture to
Il barbiere di Siviglia. This is distinct from a short development, such as in the opening movement of Mozart's Violin Sonata in G major,
K. 379. Another instance of a truncated sonata form has the development section completely omitted altogether, and the recapitulation immediately follows the exposition (even without a retransitional passage). This is known as
sonatina form. And it occurs in the second movement of
Beethoven's
Symphony No. 8. It also happens in the first movement of
Tchaikovsky's
Serenade for Strings and again in the third movement of his
Symphony No. 6. ==In concerti==