Double Whole Note - Alla Breve

Alla breve, the time signature 2/2, takes its name from the note value breve. In the mensural notation of the Middle Ages and Renaissance, it was an alternative term for proportio dupla, which meant that the brevis was to be considered the unit of time (tactus), instead of the usual semibrevis. The old symbol used as an alternative to the numerical proportion 2/1 in mensural notaton is carried over into modern notational practice, to indicate a smaller relative value per note shape, used for music in a relatively quick tempo, where it indicates two minim (half note) beats in a bar of four crotchets, while is the equivalent of 4/4, with four crotchet beats (Wright 2001).