Renaissance music Nova (see Medieval music), there could be either two or three of these for each breve (a double-whole note), which may be looked on as equivalent to the modern "measure," though it was itself a note value and a measure is not. The situation can be considered this way: it is the same as the rule by which in modern music a quarter-note may equal either two eighth-notes or three, which would be written as a "triplet." By the same reckoning, there could be two or three of the next smallest note, the "minim," (equivalent to the modern "half note")
Mensural notation and short notes (minims and crotchets), or groups of three short notes. In the 13th century, all of these were notated using only the longa and breve notes. A longa was automatically understood to fill a whole ternary metric group whenever it was in the neighborhood of other notes that did the same, i.e., whenever it was followed either by another longa or by a full group of three breves. When, however, the longa was preceded or followed by a single breve, then both filled a ternary group together. Thus, the longa had to be reduced to a value of