What is "time signature"

Time signature \Time signature\ (Music) A sign at the beginning of a composition or movement, placed after the key signature, to indicate its time or meter. Also called rhythmical signature. It is in the form of a fraction, of which the denominator indicates the kind of note taken as time unit for the beat, and the numerator, the number of these to the measure.

n. (context music English) A numerical sign placed on a stave to indicate the meter; the numerator is the number of beats per bar, the denominator represents the value of each beat

n. a musical notation indicating the number of beats to a measure and kind of note that takes a beat [syn: musical time signature]

The time signature (also known as meter signature, metre signature, or measure signature) is a notational convention used in Western musical notation to specify how many beats (pulses) are to be contained in each bar and which note value is to be given one beat. In a musical score, the time signature appears at the beginning of the piece, as a time symbol or stacked numerals, such as or (read common time and three-four time, respectively), immediately following the key signature or immediately following the clef symbol if the key signature is empty. A mid-score time signature, usually immediately following a barline, indicates a change of meter.

There are various types of time signatures, depending on whether the music follows simple rhythms or involves unusual shifting tempos, including: simple (such as or ), compound (e.g., or ), complex (e.g., or ), mixed (e.g., & or & ), additive (e.g., ), fractional (e.g., ), and irrational meters (e.g., or ).