Rather than using one second as time unit, music has its own time unit {beat, rhythm}. Beats {whole note} can divide into half beats {half note}, quarter beats {quarter note}, eighth beats {eighth note}, or sixteenth beats {sixteenth note}. Notes can sound for any number of beats or beat fractions. Notes can have 1.5 beats {dotted note, beat}, 0.75 beats {dotted half note}, 0.375 beats {dotted quarter note}, and 0.1875 beats {dotted eighth note}.
In late 12th century, besides long notes, chants began to use short notes {brevis}. Brevis had one beat. Long had two beats. One long equaled two brevis. As in poetry, brevis and long can make two-syllable, three-syllable, or four-syllable meters: pyrrhic, iamb, trochee, spondee, tribrach, anapest, dactyl, and dispondee.
Later, chants began to use notes that combined long and brevis to make "longshort" three-beat notes. Then, trochee was long-short. Dactyl was long-short-short or longshort-short-long. Anapest was long-long-longshort. Spondee was longshort-longshort. Tribrach was short-short-short.
European time units {tempus} equal to brevis began [1300 to 1400]. Tempus had two or three parts {semibreve}, each of which had two or three parts {semibreve minimae} {minimae}. Time types were three semibreves {perfect time} or two semibreves {imperfect time}, to make four time signatures {prolation}. 2/4 time had two semibreves with two minimae. 6/8 time had two semibreves with three minimae. 3/4 time had three semibreves with two minimae. 9/8 time had three semibreves with three minimae.
Outline of Knowledge Database Home Page
Description of Outline of Knowledge Database
Date Modified: 2022.0225