Time Signatures
Four-four Time Signature
The time signature is a notational convention used in Western Music to indicate the meter of a piece of music. It consists of two numbers placed one on top of the other that specify how many beats (pulses) are contained in each measure (bar), and which note value is equivalent to a beat. Time signatures appear at the beginning of a piece of music after the key signature or after the clef if the key signature is empty. Keep in mind that although time signatures may resemble fractions, they are never written with a horizontal line separating the two numbers vertically.
There are many possible time signatures depending on whether the music follows regular (or symmetrical) beat patterns or shifting beat patterns. Regular beat patterns include simple and compound meters. Shifting beat patterns include complex, mixed, and other more esoteric meters such as additive, fractional, and irrational meters.
In this course we will cover simple meters, compound meters, and mixed meters.
The Top Number
In simple meters, the top number indicates how many beats (or pulses) there are in each measure. For example, in "four-four" meter, the top number 4 indicates that there are four beats in a measure.
The following chart provides a summary of the three possible types of simple meter: those containing 2, 3, or 4 beats per measure. Thus, the only possible top numbers for simple meters are 2 (signifying duple meter), 3 (triple), and 4 (quadruple).
| Top Number | 2 | 3 | 4 |
| Beats per measure | 2 | 3 | 4 |
| Meter type | duple | triple | quadruple |
Remember
In simple meters...
- The top number indicates the number of beats per measure.
- The only possible top numbers are 2 (duple meter), 3 (triple), and 4 (quadruple).
- The bottom number indicates the note value of the beat.
The Bottom Number
In simple meters, the bottom number of the time signature represents the note value that is used as the beat. For example, in "four-four" meter, the bottom number 4 indicates that a quarter note is used as the beat. So, "four-four" is a quadruple meter with four quarter note beats in each measure.
Since the quarter note is often used as the beat, the most common bottom number for time signatures is 4. But other numbers can be used as well. The following chart explains what these bottom numbers represent. For example, an 8 on the bottom of a time signature means that an eighth note is used as the beat. Memorizing the number that represents each beat value will help you understand and recognize time signatures quickly and reliably.
| Bottom Number | 1 | 2 | 4 | 8 | 16 |
| Beat Value |  |
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Examples
Two-two meter
In two-two meter, the top number (2) indicates that there are two beats in a measure. This means that the music is in duple meter. The bottom number (2) indicates that the beat is a half note. So, there are two half note beats in every measure.
Three-four meter
In three-four meter, the top number (3) indicates that there are three beats in a measure. This means that the music is in triple meter. The bottom number (4) indicates that the beat is a quarter note. So, there are three quarter note beats in every measure.
Four-eight meter
In four-eight meter, the top number (4) indicates that there are four beats in a measure. This means that the music is in quadruple meter. The bottom number (8) indicates that the beat is an eighth note. So, there are four eighth note beats in every measure.
- Place the time signature in the correct place in the staff.
- Recognize simple time signatures quickly and accurately.