tempusn.

1889 W. S. Rockstro in Grove Dict. Music IV. 117/2 In the Middle Ages, the words ‘Tempus’, ‘Tempo’, ‘Time’ described the proportionate duration of the Breve and Semibreve only.

1954 W. G. Waite Rhythm Twelfth-Cent. Polyphony i. 15 Tempus is the equivalent of a beat taken at a tempo which would allow the human voice to execute several very rapid notes within the beat. Anonymous IV, however, wrote at a time (ca. 1280) when the brevis or tempus was in practice divided into more notes of shorter duration than was the case in the twelfth century.

1979 Early Music 7 183 The unit of measure in the 13th century was the tempus, defined by Anonymous IV as ‘a duration that is neither the smallest nor the largest, but that can be produced in a moderately short space of time, so that it can be divided into two, three, or four more notes by the human voice in rapid motion’.

1986 Early Music 14 352/2 Domenico's scheme..may..have been an attempt to reflect..the complete system of tempus, prolatio and proportio found in music.