Rondo form, based on the process of periodic thematic return, is the least formulaic of any of the Classical- era forms. The antecedent of rondo form is the medieval French rondeau. In a Classical-era rondo-form movement, the rondo theme itself is the central musical element, not the departures from that theme (the contrasting episodes), as is the case in so many Baroque-era ritornello movements. Rondos by Ludwig van Beethoven and Joseph Haydn are analyzed as examples of Classical-era rondo form.