The same way you develop any major scale.
W = Whole Step
H = Half Step
S= Start/End Degree
S - W - W - H - W - W - W - H(S)
so the Db Major scale would be:
Db - Eb - F - Gb - Ab - Bb - C - D
A-flat Major scale
D flat, E flat, F flat, G Flat, A flat, B Double flat, C flat, D flat. However, since D flat and C sharp are, essentially, the same, it would be easier to write in terms of C sharp. The scale would then read C sharp, D sharp, E, F sharp, G sharp, A, B, C sharp.
The third in a B-flat scale is D.
The dominant (fifth) degree of a D sharp major scale is A sharp.
D-flat major. It's the enharmonic equivalent.
A-flat Major scale
D flat major :)
The mediant of B flat major is D.
There are different rules. For major keys, the rule is this (by the way, # means sharp): C major scale- 0 sharps or flats G major scale- 1 sharp - F sharp D major scale- 2 sharps - F and C sharp A major scale- 3 sharps - F, C, G sharp E major scale- 4 sharps - F, C, G, D sharp B major scale- 5 sharps - F, C, G, D, A sharp F# major scale- 6 sharps - F, C, G, D, A, E sharp C# major scale - 7 sharps - F, C, G, D, A, E, B sharp. For major keys with flats: F major scale - 1 flat - B flat B flat major scale - 2 flats - B, E flat E flat major scale - 3 flats - B, E, A flat A flat major scale - 4 flats - B, E, A, D flat D flat major scale - 5 flats - B, E, A, D, G flat G flat major scale - 6 flats - B, E, A, D, G, C flat C flat major scale - 7 flats - B, E, A, D, G, C, F flat So as you might have noticed, in increasing order of sharps it is: F, C, G, D, A, E, B. And the increasing order of flats is B, E, A, D, G, C, F. If you notice the order of sharps is the opposite of the order of flats.
D flat, E flat, F flat, G Flat, A flat, B Double flat, C flat, D flat. However, since D flat and C sharp are, essentially, the same, it would be easier to write in terms of C sharp. The scale would then read C sharp, D sharp, E, F sharp, G sharp, A, B, C sharp.
b flat, d flat, f, and g
The mediant is the 3rd of the scale, so in B-flat it's D.
D natural
The third in a B-flat scale is D.
The dominant (fifth) degree of a D sharp major scale is A sharp.
F Major has a relative minor scale of D Minor.
D-flat major. It's the enharmonic equivalent.