Prolation Prolation Prolation is a term used in the theory of the mensural notation of medieval and Renaissance music to describe its rhythmic structure on a small scale, as opposed to "tempus", which described a larger scale. The term "prolation" is derived from the Latin "prolatio", first used by Philippe de Vitry in describing Ars Nova, a musical style that came about in 14th-century France. Prolation, together with tempus, corresponds roughly to the concept of time signature in modern music. Prolation describes whether a semibreve (whole note) is equal in length to two minims (half notes) ("minor prolation" or "imperfect prolation";
Symphony No. 5 (Vaughan Williams) minims in a fast 3/4 time, then minims for four bars, which create hemiolas and then crotchets. This gives the illusion that the music is accelerating, and so the pulse does not settle. When the melodic line begins, the music is divided into five bar phrases. A sense of stability is established when the theme is repeated by the viola and double bass in stable two bar phrases. However the violins enter with phrasing that does not conform to either pattern, thus adding more confusion. Using this rhythmic phrasing, the dorian line played on the violins and the aeolian woodwind