Common Forms Sectional Forms Music theory, explained with Oreos Theory Things   William Wieland
Popular Music
12-bar BluesI - I - I - I,  IV - IV - I - I,  V - IV - I - I
Song Forma a b a(B is the bridge.)
Strophic FormEvery verse uses the same music (Verse = Strophe = Stanza)
Verse / RefrainVerse 1—Refrain—Verse 2—Refrain—(etc.)
Classical Music
Binary FormA B
Ternary FormA B A'(Binary, Ternary & Rounded Binary Compared)
Rounded Binary FormA B Part of A
Sonata FormExposition   Development   Recapitulation
Rondo FormA B A C A
Theme and VariationsA  A' A''...
Bar FormA A B
Multi-movement Sonata (String Quartets and Symphonies usually follow this model.)
1st movementAllegroTonicSonata Form (but other forms including Theme & Variations are possible)
2nd movementSlowNot TonicMany forms are possible including Binary, Ternary, Rounded Binary and Sonata
3rd movementDanceNot TonicCompound Ternary (usually Minuet & Trio or Scherzo & Trio)
4th movementFastTonicRondo Form (Sonata-Rondo or Sonata Form are also possible)