Definition
A time signature tells you how many beats are in each measure (or bar) of music and what kind of note gets one beat. It looks like a fraction at the beginning of a piece. The top number indicates the number of beats per measure. The bottom number indicates which note value equals one beat (e.g., 4 means a quarter note). Think of it as the rhythmic blueprint of a song. Common time signatures are 4/4 (four beats per measure, quarter note gets one beat) and 3/4 (three beats per measure, quarter note gets one beat).