Altered Scale

The altered scale is the 7th mode of the melodic minor scale
What is the melodic minor scale?
This scale constitutes of
R 2 b3 4 5 6 7 R
For example a C melodic minor scale will be
C D Eb F G A B C
If we were to start off this scale from the 7th note and end at the 7th note it will be
B C D Eb F G A B

Tonic Solfa Version

(ti doh reh moh fah sol lah ti)
This scale becomes a B altered scale
The difference between this scale and the locrian scale
(7th mode of the major scale) is the #2
Therefore Altered Scale Will Be:
R b2 b3 3 b5 b6 b7 R
B altered scale
R = B
b2= C
b3= D
3= E
b5= F
b6= G
b7= A
R= B
Application of This Concept
The altered scale is applied over an altered dominant chord.
The B altered scale above can be used over any B altered dominant chord
e.g B dom 7 #5
LH                  RH
B                   A Eb G
Having B altered dominant which is your 7th chord that takes you to the 3 on the key of C
LH                    RH
B                      A Eb G 7
E                      D G C 3
The B altered scale serves as a passing scale to the 3 chord on the key of C..
Bass               LH                 RH
B                  A Eb G            B altered scale
E                  D G C              E G C
Note: You could run the scale up the keyboard or down the keyboard
Also, the altered scale could also serve as a 5 dominant passing scale to the 1 chord
In the key of C, the 5 is G
Altered Scale: R b2 b3 3 b5 b6 b7 R
Therefore a G altered scale will be
R= G
b2= Ab
b3= Bb
3= B
b5= Db
b6= Eb
b7= F
R= G
Bass             LH                      RH
G                 F B Eb                 G altered scale
C                 E G C                  E G C