Mensural notation recoverable from the modern text. While 19th and early 20th century editions of Renaissance music often preserved the large note values of the originals, including breves and longs, most modern editions will use scaled-down note values in order to match modern reading habits regarding tempo and beat structure. For 16th century music, a frequent scheme is diminution by a factor of 2 (i.e., rendering semibreves as modern minims), in a modern "alla breve" bar. Older music might be diminished by a factor of 4 (rendering semibreves as crotchets) or sometimes 8 (rendering breves as crotchets). For 13th-century pieces, diminution by
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