Editing Sonata form (section)

===Exposition===
{{Main article|Exposition (music)}}
{{multiple image|header=[[Joseph Haydn|Haydn's]] Keyboard Sonata, [[Hoboken-Verzeichnis|Hob.]] XVI: G1, I|direction=vertical|width=330
|image1=First theme Haydn's Sonata in G Major.png
|caption1=First theme (G major) and transition from counterstatement (to D major), mm. 1–12<ref name="B&S" />{{rp|136}}[[File:First theme Haydn's Sonata in G Major.mid]]
|image2=Transition Haydn's Sonata in G Major.png
|caption2=Start of second subject (D major), mm. 13–16 [[File:Transition Haydn's Sonata in G Major.mid]]
|image3=Second theme Haydn's Sonata in G Major.png
|caption3=End of second subject and Codetta (D major), mm. 17–28 [[File:Second theme Haydn's Sonata in G Major.mid]]
|image4=Development Haydn's Sonata in G Major.png
|caption4=Development, mm. 29–53<ref name="B&S" />{{rp|138–139}} [[File:Development Haydn's Sonata in G Major.mid]]
|image5=Retransition Haydn's Sonata in G Major.png
|caption5=Retransition, mm. 54–57<ref name="B&S"/>{{rp|140}} [[File:Retransition Haydn's Sonata in G Major.mid]]
|image6=Coda Haydn's Sonata in G Major.png
|caption6=Recapitulation, mm. 58–80<ref name="B&S"/>{{rp|140–141}} [[File:Coda Haydn's Sonata in G Major.mid]]
}}
The primary thematic material for the movement is presented in the exposition. This section can be further divided into several sections. The same section in most sonata form movements has prominent harmonic and thematic parallelisms (although in some works from the 19th century and onward, some of these parallelisms are subject to considerable exceptions), which include:
* ''First subject group'', ''P'' (Primary) – this consists of one or more [[theme (music)|themes]], all in the [[Tonic (music)|tonic]] key. Although there are exceptions, most pieces follow this form.
* ''[[transition (music)|Transition]]'', ''T'' – in this section the composer modulates from the key of the first subject to the key of the second. If the first group is in a major key, the second group will usually be in the [[Dominant (music)|dominant]] key. However, if the first group is in a minor key, the second group will usually be the [[relative major]].
* ''Second subject group'', ''S'' – one or more themes in a different key (typically the dominant) from the first group. The material of the second group is often different in rhythm or mood from that of the first group (frequently, it is more lyrical) and is often stated at a piano dynamic.
* ''Closing zone (or closing area)'', ''C''  – a suffix after the end of the second subject group that reinforces the new key area. C involves musical material that differs from what was heard in S, and often includes distinctly new thematic material.
The exposition is commonly repeated, particularly in classical and early romantic works, and more likely in solo or chamber works and symphonies than for concerti. Often, though not always, first and second endings are employed during the last measure(s) of the exposition. The first ending to point back to the tonic, where the exposition began, and the second ending to point towards the development.