Typically, a piece consists of several bars of the same length, and in modern musical notation the number of beats in each bar is specified at the beginning of the score by the top number of a time signature (such as 3/4), while the bottom number indicates the note value of the beat (the beat has a quarter note value in the 3/4 example). It also makes written music easier to follow, since each bar of staff symbols can be read and played as a batch. Dividing music into bars provides regular reference points to pin point locations within a piece of music. In musical notation, a bar (or measure) is a segment of time defined by a given number of beats, each of which are assigned a particular note value.
