Definition: A time signature is a large fraction written at the beginning of a staff after the clef, and – if applicable – the key signature. A time signature expresses the meter of a song, and is understood as follows:
See common time and cut time.
- The top number indicates how many beats are in a measure; usually between 2 and 12, but theoretically, any number (or even a fraction) may be used.
- The bottom number gives away the length of the beat (2 = half note; 4 = quarter note; 8 = eighth note, and so on).
Rules of the Time Signature
- In piano music, the time signature only needs to appear on the very first staff of the composition. However, modern notation tends to repeat the signature on each line of music.
- If a change of meter takes place on a new line of music, the new time signature is first written at the end of the staff above it (after the last bar line), and then repeated at the beginning of the staff it affects.
- A change of meter occuring mid-line is preceded by a double barline; if the change is mid-measure, a dotted double barline is used.
► Quiz! Test Yourself on Notes & Time Signatures
See common time and cut time.
Also Known As:
- meter signature
- indicazione di misura; segno mensurale (It)
- indication de la mesure; signature rythmique (Fr)
- Taktangabe; Taktzeichen (Ger)


