Time Signature

The Rhythm of the Music

A Time Signature consists of 2 figures in the form of a fraction, placed together at the beginning of every piece of music. It defines the rhythm and structure of the music helping musicians follow the appropriate beat and count the measures accurately.

Tempo is the speed or rate of a piece of music usually measured in beats per minute (bpm), whereas rhythm is the way in which the tempo is played - the division of musical ideas or sentences into metrical portions. It is the timing of musical sounds and silences.
A Time Signature consists of an upper numeral and a lower numeral.
The upper numeral indicates how many beats there are in a bar.
The lower numeral indicates the note value which represents one beat.
Example: In 4/4 time, there are 4 beats in each bar with each beat represented by a quarter note.
Example: In 6/8 time there are 6 beats in each bar with each beat represented by an eighth note.
In a musical score, the time signature appears at the beginning of the piece, immediately following the key signature. This can be in the form of a time symbol, 𝄵 which represents cut time (2/2), or in the form of stacked numerals such as 4/4, 3/4, 6/8 etc. 4/4 time can also be represented by the symbol 𝄴
If the piece is in the key of C Major or A minor where there is no key signature (sharps or flats), the time signature is placed straight after the Clef sign.
Sometimes you will see another time signature midway through a piece. This occurs when there is a change of rhythm or timing. When this occurs you will see the new time signature following a bar line. All the music shown after the new time signature will be played according to the new time.
Time signatures not only dictate how many beats to count but also influence the feeling of the music. For example, 3/4 feels like a waltz, whereas 4/4 feels more grounded and steady.

Common Time Signatures

2/2 - denotes 2 half notes or 2 minim beats to the bar
2/4 - denotes 2 quarter notes or 2 crotchet beats to the bar (♩)
3/4 - denotes 3 quarter notes or 3 crotchet beats to the bar (♩)
4/4 - denotes 4 quarter notes or 4 crotchet beats to the bar (♩)
3/8 - denotes 3 eighth notes or quaver beats to the bar (♪)
6/8 - denotes 6 eighth notes or quaver beats to the bar (♩)

Common or 4/4 time: four beats per measure, and each beat is the duration of a quarter note or crotchet.

Alla Breve (cut time): 2 half-note or minim beats per bar

Time is divided into 2 classes: Simple and Compound

Simple Time consists of undotted notes for beats each divisible into 2 equal parts
Compound Time consists of dotted notes for beats each divisible into 3 equal parts

Each class contains 3 kinds:

a) Duple
b) Triple
c) Quadruple

Simple Time

Simple Duple has 2 undotted notes for beats in each bar - each divisible into 2 equal parts
Simple Triple has 3 undotted notes for beats in each bar - each divisible into 2 equal parts
Simple Quadruple has 4 undotted notes for beats in each bar - each divisible into 2 equal parts

Compound Time

Compound Duple has 2 dotted notes for beats in each bar - each divisible into 3 equal parts
Compound Triple has 3 dotted notes for beats in each bar - each divisible into 3 equal parts
Compound Quadruple has 4 dotted notes for beats in each bar - each divisible into 3 equal parts

Dotted Notes

When a dot is placed after a note, the time of the note is increased by half again.

A dotted whole-note: 4 beats + 2 beats (½ of 4 beats) = 6 beats in total
A dotted half-note: 2 beats + 1 beat (½ of 2 beats) = 3 beats in total
A dotted quarter-note: 1 beat + ¹⁄₂ beat (½ of 1 beat) = 1 ½ beats in total
A dotted eighth-note: ¹⁄₂ + ¹⁄₄ (½ of ½ beat) = ³⁄₄ of a beat in total

The following shows the different note-names used in American and British Nations.

Name (American)	Name (British)	Beats
Dotted Whole Note	Dotted Semibreve	6
Dotted Half Note	Dotted Minim	3
Dotted Quarter Note	Dotted Crotchet	1 ½
Dotted Eighth Note	Dotted Quaver	³⁄₄

Accent & Syncopation

Accent is stress or emphasis on certain notes. When the accent is moved to a weak beat, syncopation is formed.

In Duple Time: (2 beats/bar) The accents are Strong - Weak
In Triple Time: (3 beats/bar) The accents are Strong - Weak - Weak
In Quadruple Time: (4 beats/bar) The accents are Strong - Weak - Medium - Weak

Syncopation is also formed when a note that is just before or just after the beat is stressed. You may have a 4/4 bar | 1& 2& 3& 4& | where the accent is placed on the & of 4&...

Normally the accent would be on beats 1 and 3, and with syncopation, beats 2 and 4, e.g. reggae. But in this example, the syncopated beat lies beyond the normal beats in the bar... & of 4&.

The following is an excerpt from Wikipedia...

Technically, "syncopation occurs when a temporary displacement of the regular metrical accent occurs, causing the emphasis to shift from a strong accent to a weak accent." "Syncopation is," however, "very simply, a deliberate disruption of the two-beat or three-beat stress pattern, most often by stressing an off-beat, or a note that is not on the beat..." learn more about Syncopation at Wikipedia

The Use of Simple & Compound Time Signatures

Simple Time Signatures and where they are used

4/4 : Common Time - Widely used in most forms of Western popular music. Most common time signature in rock, blues, country, folk, funk and pop including a wide variety of modern genres introduced over the last few decades.

2/2 : Cut Time or Alla Breve - commonly used in fast orchestral music and marches. You will also find it in musical theatre and some forms of popular music.

4/2 : Never found in early music and rare since 1600, although Brahms and other composers used it occasionally.

2/4 : Used for polkas and marches.

3/4 : Used for waltzes, minuets, scherzi, country & western ballads, and sometimes used in pop.

3/8 : Also used for the above, but usually suggests a faster tempo.

Compound Time Signatures and where they are used

6/8: Polkas Double jigs, tarantella, sega, barcarolles, marches, loures, and some rock music.

9/8: Compound Triple Time - occurs rarely - used in triple or 'slip' jigs.

12/8: Commonly used in slow blues. It is also known as the doo-wup or shuffle. It is being used in some forms of rock music and you will hear it in some jigs... a popular example of this is .