The time signature (also known as "meter signature") is a notational convention used in Western musical notation to specify how many beats are in each bar and what note value constitutes one beat. Time signatures indicate meter, but do not necessarily determine it.
Most time signatures comprise two numbers, one above the other. In text (as in this article), time signatures are written in the manner of a fraction: the example shown at right would be written 3/4.
In a musical score, the time signature appears at the beginning of the piece, immediately following the key signature (or immediately following the clef if the piece is in C major or A minor). A mid-score time signature, usually immediately following a barline, indicates a change of meter.