Time Signatures
Time signatures define the meter of the music. Music is "marked off" in uniform sections called bars or measures, and time signatures establish the number of beats in each. This does not necessarily indicate which beats to emphasize, however, so a time signature that conveys information about the way the piece actually sounds is thus chosen. Time signatures tend to suggest prevailing groupings of beats or pulses.
Specific time – simple time signatures
The bottom number represents the note value of the basic pulse of the music (in this case the 4 represents the crotchet or quarter-note). The top number indicates how many of these note values appear in each measure. This example announces that each measure is the equivalent length of three crotchets (quarter-notes). For example, 3 / 4 is pronounced as "three-four time" or "three-quarter time".
The bottom number represents the note value of the basic pulse of the music (in this case the 4 represents the crotchet or quarter-note). The top number indicates how many of these note values appear in each measure. This example announces that each measure is the equivalent length of three crotchets (quarter-notes). For example, 3 / 4 is pronounced as "three-four time" or "three-quarter time".
Common time
This symbol represents 4 / 4 time. It derives from the broken circle that represented "imperfect" duple meter in fourteenth-century mensural time signatures.
This symbol represents 4 / 4 time. It derives from the broken circle that represented "imperfect" duple meter in fourteenth-century mensural time signatures.
Alla breve or Cut time
This symbol represents 2 / 2 time, indicating two minim (or half-note) beats per measure. Here, a crotchet (or quarter note) would get half a beat.
This symbol represents 2 / 2 time, indicating two minim (or half-note) beats per measure. Here, a crotchet (or quarter note) would get half a beat.