NEHITA ABRAHAM
How Perfect are
The Perfect Intervals?
If you have been to any music class, you’re bound to learn about intervals in the
music language. Soon enough you will hear the term: “Perfect Intervals”. So, if
you’ve ever wondered what’s so perfect about them? Just keep reading.
No glitch with the right pitch!
What does the term “pitch” mean?
A pitch of a certain note tells us how high or low the note
sounds.
What does the term “interval” mean?
An interval is the distance between any two pitches or any two
notes.
While scientists often describe the difference in pitch
between two notes, as the difference between their frequency,
musicians on the other hand like to see the difference between
two notes as intervals. We can simply calculate how many
semitones have moved up or down and it’s easy! For example,
you can say "B natural is a half step below C natural", or "E flat
is a step and a half above C natural". But when we talk about
larger intervals in the major/minor system, there is a more
convenient and descriptive way to name them.
This concept is so important that it is almost impossible to
talk about scales, chords, harmonic progression, cadence, or
dissonance without referring to intervals.
Perfect Pitch or Pitch Perfect?
Unisons, octaves, fourths(4th), and fifths(5th) are called perfect
intervals.
A perfect interval is an interval that is not major, minor,
augmented or diminished. It always remains perfect.
Sure, they can be augmented or diminished if we move a note
up or down. A perfect interval becomes augmented when G-C
(perfect 4th) is changed from G-C# (an augmented 4th). But
without changing the note, a perfect interval always remains
perfect.
Let’s test this! Let’s turn things upside down! (literally)
24
The
Score Magazine
highonscore.com
Let’s say we want to turn an interval upside down, or inverted.
When you do that with C-E ( a major third) the inversion gives
us E-C ( a minor 6th). Woah! A major can become a minor
when we shift the position? Yes, that’s why it’s important to
remember that intervals are based on an absolute distance
in between semitones and not if they are in a minor or major
scale. Minor intervals are not minor because they are found in
the minor scale and the same goes for the major.
Majors become minors, majors become minors, augmented
becomes diminished, The exceptions to this inversion rule are
the octaves, 4th and 5th.
C- F is a perfect 4th
F-C is a perfect 5th.
The interval stays at perfect, that hasn't changed.
Even still, why do we innately feel that certain intervals are
consonant( sounds that sound good together)? And ever go so
far as to call them “perfect” ?
In simple words, if we examine the acoustics or sound waves(
Frequency and Wavelength), the notes of the perfect interval
are very closely related. Because they are so closely related,
they sound particularly good together, a fact that has been
noticed since at least the times of classical Greece, and
probably even longer. (Both the octave and perfect fifth have
prominent positions in most of the world's musical traditions.)
This makes them sound really particularly good together.
One person to identify this was Pythagoras (Yes, the same guy
whose theories annoy you during exams), and possibly many
other Greeks at the time noticed this too. We can tell that they
liked it, by the fact that in most musical traditions, the octave
and perfect 5th have a prominent position.
So, to go so far as to call these intervals “perfect”? Guess it
sounds and calculates perfectly!