Download Time Signatures Demystified

Time Signatures Demystified
Time signatures are musical symbols
that use numbers to give information
to the performer, namely:
• How many beats are in each measure?
• What note value receives one beat? (We call
this note value the ‘beat note.’)
• The numbers of a time signatures are written
only once at the beginning of the composition.
That time signature remains in force until the
end of the composition or a change of time
signature later in the piece.
• The numbers are written one above the other,
but do not use a line between them (like
fractions).
• The top number refers to the number of beats
in the measure (though not always directly).
• The bottom number refers to the beat note
(but not always directly).
There would be no problem if time
signatures were written something
like:
or
The first time signature above means 2 beats
per measure and the quarter note is the beat
note. The second time signature means 3 beats
per measure and the dotted eighth note is the
beat note.
Instead, music uses numbers on the
bottom of a time signature to represent
note values.
• In MUSC 141, we will learn about two
important families of time signatures:
• Simple meters: these are meters in which the
beat divides evenly into halves.
• Compound meters: these are meters in which
the beat divides evenly into thirds.
Simple Meters
The top number indicates the number of beats
in a measure. Those numbers typically are:
• 2 (simple duple meter, 2 beats per measure)
• 3 (simple triple meter, 3 beats per measure)
• 4 (simple quadruple meter, 4 beats per
measure)
Simple Meters (cont.)
The bottom number indicates the beat note.
The most common numbers are:
•
•
•
•
2 (half note gets the beat)
4 (quarter notes gets the beat)
8 (eighth note gets the beat)
16 (sixteenth note gets the beat)
Simple Meters (cont.)
Two simple time signatures in particular have
special symbols that are often used in place of the
numbers:
• The signature is known as ‘common time’ and
is represented by the symbol
• The signature is known as ‘cut time’ (or alla
breve) and is represented by the symbol
Compound Meters
Compound meters are often challenging to
beginning musicians because they haven’t
encountered much music written in these
meters, or they may have previously learned an
incorrect meaning of these meters
Compound Meters (cont.)
Recall that in simple meter the beat (note) is
subdivided in halves, and that this matches
perfectly with the normal subdivision of note
values, for example:
Compound Meters (cont.)
But in compound meter, how can we have a
beat (note) that subdivides evenly into a group
of three?
The answer is
, a dotted note!
Compound Meters (cont.)
• So, in compound meter the beat note is ALWAYS a
dotted note.
• The problem is that dotted notes cannot be
represented by a number (which show its
relationship to the whole note).
• Instead, the numbers that make up a compound
time signature have different meanings than in
simple time signatures.
• Rather than refer to beats, the numbers refer to
the subdivisions of the beat!
Compound Meters (cont.)
• The top number tells us how many total
subdivision notes are in a measure.
• Since every beat divides into three subdivision
notes, the top number of the time signature
will ALWAYS be a multiple of three.
• The most common top numbers are 6, 9, and
12. Let’s see how we arrive at those numbers.
Compound Meters (cont.)
• Compound Duple meter: 2 beats per measure
x 3 subdivisions = 6
• Compound Triple meter: 3 beats per measure
x 3 subdivisions = 9
• Compound Quadruple meter: 4 beats per
measure x 3 subdivisions = 12
Compound Meters (cont.)
• To review, the top number tells us how many
subdivision notes are in a measure.
• The bottom number tells us what that
subdivision note value is.
• Fortunately, these bottom numbers refer to the
same type of note as the bottom numbers in
simple meter, namely:
4 = quarter note
8 = eighth note
16 = sixteenth note
Compound Meters (cont.)
• So to determine the beat note in compound
meter, simply add together three of the
subdivision notes, which the bottom number
of the time signature tells us.
• To determine the number of beats in the
measure, simply divide the top number by 3.
Compound Meters (cont.)
• As an example take the time signature
.
• Divide the top number (12) by 3. 12 ÷ 3 = 4,
which means 4 beats in the measure (thus, a
quadruple meter).
• The bottom number (16) tells us the sixteenth
note is the subdivision note, so if we add up
three of them we get:
• The dotted eighth note is the beat note.
Let’s listen to some music in compound meter.
• Sometimes the compound meter can move at
a moderate tempo:
• Or the tempo can move a lot quicker:
• Popular music also makes use of compound
meter; some older tunes:
• And some newer popular music:
• And especially classic R & B (Rhythm & Blues):