Custom Scale using music21's scale class to inherit "deriveAll" function

Question

What is the proper way to define a custom scale that inherits the attributes of the scale class?

Should I include my class in music21/scale/__init__.py

class myAbastract(AbstractScale):
    '''
    A pseudo my-scale.
    '''
    def __init__(self):
        super().__init__()
        self.type = 'Abstract My Name'
        self.octaveDuplicating = True
        self.dominantDegree: int = -1
        self.buildNetwork()

When I defined myScale in the main.py, it seems it doesn't inherit "deriveAll()" method/function.

pitchListStrs = 'a b` c d e f g a'.split()
pitchList = [pitch.Pitch(p) for p in pitchListStrs]
myScaleA = scale.ConcreteScale(pitches=pitchList)
[str(p) for p in myScaleA.getPitches('E-5', 'G-7')]

myScale = myScaleA.abstract
mySol =scale.ConcreteScale()
mySol.tonic = pitch.Pitch('D')

But then, deriveAll is not defined:

myScale.deriveAll(['E5', 'F5', 'G5', 'A5', 'B`5', 'C6', 'D6', 'E6'])
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'AbstractScale' object has no attribute 'deriveAll'

Answer 1

deriveAll is a routine defined on ConcreteScale instances. You attempted to call it on an instance of AbstractScale. Try calling it on your variable myScaleA, which is concrete.