Scale degree also indicates the
interval
or tonal distance from the beginning note
of that scale. For example, the tonal distance from C to G is 3½ steps. In the dia-
gram at the bottom of page 10, we see that in the key of C major the fifth note is
G. This interval is called a
perfect 5th
(often just called a
fifth
).
In the B Locrian mode, the distance between the first note and the fifth note (F)
is 3 steps. The interval between B and F is a half step less than a perfect 5th.
Using the scale degrees of the major scale to measure this distance, we call this
shorter interval a
diminished 5th
. The scale degree and spacing of notes in the
diatonic major scale is the “yardstick” by which intervals in other scales and
modes are measured.
Altered Chords
Occasionally, you may see a chord written G13<9 or G11>9. Chords like these
have flatted or sharped one or more of the notes of the naturally occuring scale
degree. Whenever a note of a chord is changed and the change results in a note
that does not belong to the scale from which the chord is derived, the chord is
said to be
altered
.
Because altered chords use notes outside the diatonic scale they often produce
a
dissonant
sound. These chords are used to create a feeling of tension in a
song. The chord that follows an altered chord usually relieves the tension.
w
h
C
w
w
h
w
w
w
w
h
w
w
D
E
F
G
A
B C
D
E
F
G
A
1st
2nd
3rd 4th
5th
6th
7th
9th
10th 11th
12th
13th
C
D
E
G
A
B C
D
E
F
G
A
B
G13
C
D
E
G
A
B C
D
E
F
G
A
A<
B
G13<9
Cmaj7
C Major Scale
G Mixolydian Mode
Flatting the 9th creates a note that does
not occur in the key of C major.
11
w
h
w
w
h
w
w
w
w
h
w
w
1st
root
2nd
3rd 4th
5th
6th
7th 8th
octave
9th
10th 11th
12th
13th
The Diatonic scale pattern is the musical equivalant of a yardstick.
