🔒 Get a scale based on the number of sharps of flats

[lusty current]

https://github.com/nautrw/mtheorypy
I am trying to reinvent the wheel and make a library to programatically manipulate music. In the keys.py file, I have a dataclass for keys, which holds the number of sharps or flats. I also have a function to get the key signature of a key. How can I get the notes in a specific scale according to the key signature? (The file contains my failed attempt at implementing it)

[molten raven]

@lusty current

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[small crow]

can you explain it in a simpler way just using numbers and letters and such data for us that doesn't know music theory?

[lusty current]

its easier to do arithmetic on them

[lusty current]

bump

[austere holly]

Dictionary with the scale as the key and notes as the value?

[lusty current]

thats probably the way i should do it but

ive seen other libraries do it programatically

[thick hound]

Would it not just be a case of working out each scale's procession in semitone values then mapping keys to offsets?

[lusty current]

hm

[thick hound]

Major, minor, harmonic, melodic, etc, then plus offset.

[austere holly]

A sharp/flat is just a modifier, so you can make a scale using just the base note, a list of offsets for the scale type, and apply the sharps/flats.

[lusty current]

but i still need the flats and sharps

if i bring down the c scale a step down i get bcdefgab but they are all natural

so how do i apply the sharps and flats

[austere holly]

Like usual? Sharp = +1 half step, flat = -1

[thick hound]

Apply the naming from the key sig.

[lusty current]

how would i go about that

the key sig function just gives a list of numbers corresponding to notes

[thick hound]

My music theory is very rusty. But if you have a given absolute note in a scale and it matches an accidental in the sig, you'd be able to have another mapping of absolute notes:names per key.

I don't think I'm explaining very well.

If you write out a dictionary mapping of keys to scale notes manually, you might start to be able to see patterns you can condense into algorithms.

[lusty current]

ig

[lusty current]

thx for the help

!solved

[molten raven]

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