Editing Sonata rondo form (section)

== Structure ==

=== Sonata and rondo forms ===
[[Rondo form]] involves the repeated use of a [[Theme (music)|theme]] (sometimes called the "refrain") set in the [[Tonic (music)|tonic]] key, alternating with episodes, resulting in forms such as ABACA (the five-part rondo) or ABACADA (the seven-part rondo). In a rondo, the refrain (A) may be varied slightly. The episodes (B, C, D, etc.) are normally in a different [[Key (music)|key]] than the tonic.

[[Sonata form]] is a classical form composed of three main sections, namely [[Exposition (music)|exposition]], [[Development section|development]], and [[recapitulation (music)|recapitulation]]. A sonata may begin with an [[introduction (music)|introduction]], which is commonly slower than the remainder of the movement. After that, there is an exposition, whose purpose is to present the movement's main thematic material. This takes the form of one or two themes or theme groups, the second of which is commonly in a related key. The exposition may conclude with a short [[codetta]] or closing theme and may be repeated. This is followed by the development section, in which existing thematic material may be presented in new harmonic and textural contexts or entirely new material may be introduced. Next comes the recapitulation, where all themes or theme groups from the exposition are presented again but now in the tonic key. Sonatas may optionally end with a final large section called the [[Coda (music)|coda]].

The following shows the structure of sonata form. In the notation, a single prime (') means "in the dominant" and a double prime (") means "in remote keys".

:[A B']<sub>exp</sub> [C"]<sub>dev</sub> [A B]<sub>recap</sub>

Occasionally, sonata form includes an "episodic development," which uses mostly new thematic material.  Two examples are the first movements of [[Wolfgang Amadeus Mozart|Mozart]]'s [[Piano Sonata No. 10 (Mozart)|piano sonata K. 330]] and [[Ludwig van Beethoven|Beethoven's]] [[Piano Sonata No. 9 (Beethoven)|piano sonata Op. 14, no. 1]].<ref>For further discussion see Rosen (1997, 51).</ref>  The episodic development is often the kind of development that is used in sonata rondo form, to which we now turn.

=== Sonata rondo form ===
Sonata rondo form combines features of the five-part rondo and sonata form.<ref>{{Cite book |last=Caplin |first=William E. |url=https://www.worldcat.org/oclc/567929606 |title=Classical Form |date=1998 |publisher=Oxford University Press |isbn=1-60256-121-4 |location=Oxford |pages=235 |oclc=567929606}}</ref> The simplest kind of sonata rondo form is a sonata form that repeats the opening material in the tonic at the end of the exposition and recapitulation sections.

:[A B' A]<sub>exp</sub> [C"]<sub>dev</sub> [A B A]<sub>recap</sub>

By adding in these extra appearances of A, the form reads off as '''AB'AC"ABA''', hence the alternation of A with "other" material that characterizes the rondo.  Note that if the development is an episodic development, then C" will be new thematic material—thus increasing the resemblance of sonata rondo form to an actual rondo.

==== "Six-part" variants ====
[[Wolfgang Amadeus Mozart|Mozart]] sometimes used a variant type of sonata rondo form in which the first "A" section of the recapitulation is omitted. Thus:

:[A B' A]<sub>exp</sub> [C"]<sub>dev</sub> ['''B A''']<sub>recap</sub>

Mozart's purpose was perhaps to create a sense of variety by not having the main theme return at such regular intervals. He used the form in the finales of his [[Piano Quartets (Mozart)#Other chamber music|piano quartets]] and a number of his [[Mozart piano concertos|piano concertos]].

Another six-part sonata rondo form may be written as:

:[A B' A]<sub>exp</sub> [C"]<sub>dev</sub> ['''A B''']<sub>recap</sub>

This instance occurs in the 4th movement of Tchaikovsky's Symphony No. 6 in B minor.