A Dictionary of Music and Musicians/Evacuatio

EVACUATIO (Ital. Evacuazione; Germ. Ausleerung; Eng. Evacuation). A term used in the 15th and 16th centuries, to denote the substitution of a 'void' or open-headed note for a 'full,' or closed one; e.g. of a Minim for a Crotchet. The process was employed, both with black and red notes, and continued for some time after the invention of printing; but, its effect upon the duration of the notes concerned differed considerably at different epochs. Morley,^[1] writing in 1597, says 'If a white note, w^h they called blacke voyd, happened amongst blacke full, it was diminished of halfe the value, so that a minime was but a crotchet, and a semibriefe a minime,' etc. But, in many cases, the diminution was one-third, marking the difference between 'perfection' and 'imperfection'; or one-fourth, superseding the action of the 'point of augmentation.' For the explanation of some of these cases, see vol. ii. p. 471.

[ W. S. R. ]

1. 'A Plaine and Easie Introduction.' Annotation at the end of the volume, referring to p. 9.