Answer:
The rondo form is an extension of the ternary form in that it keeps a similar pattern but does not stop at just three sections. A RONDO/RONDEAU FORM generally consists of some symmetrical pattern of a first theme, presentation of new theme, and return to the first theme before continuing on to another theme.
Ternary form is a symmetrical structure in music most often represented by the letters ABA. The A represents a musical idea or ideas, the B represents new, contrasting material, and the final A represents a return to the familiar music heard in the opening of the piece.
