What is the patterns of beats by which music measured?

The patterns of beats by which music is measured is called meter. Meter is the basic rhythmic structure of a piece of music and it is established by the regular recurrence of beats. The meter of a piece of music is indicated by the time signature, which is a number written at the beginning of the staff. The upper number of the time signature indicates the number of beats in each measure. The lower number indicates the note value that represents one beat.