Summary of Time Signatures

The time signature indicates the metre or rhythmic pattern, of the music.

A time signature contains two numbers, one written above the other on the staff.  These numbers are written in bold type after the clef symbol and key signature, on the first line of a piece of music. The picture on the left illustrate a time signature of 3 quarter note beats per bar. When referred in text, it may be written like an arithmetic fraction, such as 3/4.  

 The upper number indicates how many beats per bar. It is the numerator (the upper digit) of a fraction. Common values are 2 (duple time), 3 (triple time) and 4 (quadruple time). 

The lower number indicates the duration of each beat. It is the unit of measurement in relation to the semibreve or whole note. It is the denominator (the lower digit) of the fraction.  The most common value is 4, indicating crotchet or quarter note beats. As an example,  2/4  means two crotchet or quarter-note beats per bar.  Other values are 8 and 2. A value of 8 means each beat or pulse is an eighth note or quaver, whereas a value of 2 means each beat is a minim or half note.

The first beat of the bar is  given a strong accent, other beats are weaker. This establishes a strong rhythmic pattern of strong and weak beats for the music. 

There are two kinds of time signature, classified by the way beats are subdivided.  Simple times have binary beats, that is they are usually divided into two or four. Examples include 2/4   3/4   4/4. Compound times have ternary beats, that is they are divided into 3 parts. The most frequently used example is 6/8,   which is compound duple time, with 2 strong beats,  each a dotted crotchet in length, subdivisible into 3 quavers Other compound times include 9/8   12/8  and 6/4.


TheoryTimeSignature.htm     01/10/06 18:50        MENU -> Theory ->  Rhythms and tempo  ->  Time Signatures  ->  Intro to Time Signatures