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";
Grace note the bar in which they are contained - and therefore, do not require other notes to be dropped from the bar to keep the time signature intact. In bagpipe music there is extensive use of grace notes. Indeed, because the chanter is not tongued but supplied by a continuous air source from the bag, grace notes are sometimes the only way to differentiate between notes. For example, inserting a grace note between two crotchets (quarter notes) played at the same pitch is the only way to indicate them as opposed to them sounding like a single minim (half note). Various