JimmyM is an excellent and very knowledgeable bass player but that statement about learning the one and only chromatic scale (starting with the note X ?) got me confused![]()
I think the point was that no matter what you want to call a specific interval or chord, or mode, or scale, they're all just different ways of looking at the relationships of notes to each other.
But underneath all of that are the 12 tones (i.e. chromatic scale) that make up an octave in Western music. Whether you think about subsets of those 12 tones in terms of 'standard' scales or modes (two different ways thinking about music theory) they remain the same.
But in the larger scheme of things, a note either works or doesn't work within the context of what else is being played with it - which is to say the song or passage.
So don't get overly hung up on music theory. It's a useful tool for gaining a deeper insight into how music works. But it's still just a tool. Not some cosmic truth.