By convention, two special symbols are sometimes used for and : The symbol is sometimes used for time, also called common time or imperfect time. The symbol is sometimes used in place of and is called alla breve or, colloquially, cut time or cut common time. These symbols derive from mensural time signatures, described below.
by convention two special symbols are sometimes used for and  the symbol is sometimes used for time also called common time or imperfect time the symbol is sometimes used in place of and is called alla breve or colloquially cut time or cut common time these symbols derive from mensural time signatures described below