The standard method of denoting the meter of a piece of music. The time signature usually appears at the beginning of a piece of written music, and anywhere in the music where it changes. As written the time signature appears to be a fraction, but isn’t. The top number tells you how many beats there are per measure and the bottom number tells you what kind of note constitutes a beat. The numbers 6/8, for instance, mean six beats per measure with an eighth note getting one beat.