Characteristic of all rondo forms is the regular returns of an (instrumental) refrain.
The phenomenon rondo has a long history. In the course of history a variety of schemes are developed:
the most simple one is A-B-A-C-A-D-... also called Italian rondo.
Lully introduced a rondo with two couplets: A-B-A-C-A, also called French rondo. This type was around 1750 a European standard. In the 17th and 18th century we see a continuing development into late classical works, of which the sonata rondo or Viennese rondo form is a special one. It has the scheme A-B-A-C-A-B-A, with the C section having characteristics of a development section. Also in the 19th and 20th century rondo forma are still being composed (Schubert, Chopin, Schumann, R. Strauss, Bartók, etc.)