I can see the construction from D onwards - jumps of 7, but how did you get to D? The instruction was 7)semi tones down, which from A is D "in previous scale"), but what about the 5 semi tones up?
One new question that popped in my mind- is this series of instructions (7down, 5up) a reverse engineering of the A major sequence to fit the 7- jump rule or is there some theory about it? I have no clue what different scales even mean or what major and minor means. Feel free to ignore the new questions (or the old one!)
The blog means two different sequences of jumps. The sequence of down-jumps begins from A. Then the sequence of up-jumps begins from A.
{jumps down: 1, jumps up: 5}
First, you start from A, and execute the down-jumps. In this case, there is only one. Then you start again from A (returning to A is not counted as a jump), and execute the up-jumps.
> Up two 7-semitone steps and down four gives you A minor.
Up-jump sequence: A, up to E, up to B.
Down-jump sequence: A, down to D, down to G, down to C, down to F.
Sort: A B C D E F G
I don't know what's behind this idea, or how useful it is. It seems to work, though. But I think there are simpler ways to construct the scales. Or just memorize them.
A (440 Hz), down to D. A, up to E, up to B, up to F#, up to C#, up to G#.
Sort: A B C# D E F# G#. This is the A major scale.