Binary Form (2-part form) Theory Things   William Wieland
Continuous or Open Binary (A does not end on tonic.)
Example: Corelli Sarabanda (Largo) from Violin Sonata op. 5 no. 7
Sectional or Closed Binary (A ends on tonic.)
Examples: Greensleeves and Brahms “Lullaby”
Repeat signs are optional and do not change the form.

A and B often share material. B can develop motives of A and explore new keys like the development of a sonata.

Symmetrical Binary: A = B in length.
Asymmetrical Binary: A & B differ somewhat in length. (B is usually a bit longer.)