In theory it is impossible for a scale to have but a flat and a sharp but if it is in inharmonics then yes it is possible to have a flat and a sharp just depends on how you look at it.
The dominant (fifth) degree of a D sharp major scale is A sharp.
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.
there is no F# scale on Eb saxaphone....
There is no difference in terms of each scale would sound, as F-sharp and G-flat are the same exact note. However, when notated on sheet music, they would look different, as the F-sharp scale would use only sharps, and the G-flat scale would use only flats.
UP: d sharp e sharp f sharp g sharp a sharp b sharp c double-sharp d sharp DOWN: d sharp c sharp b natural a sharp g sharp f sharp e sharp d sharp
The dominant (fifth) degree of a D sharp major scale is A sharp.
C, C sharp/D flat, D, D sharp/E flat, E, F, F sharp/G flat, G, G sharp/A flat, A, A sharp/B flat, B, C.
No. There are a (plus a flat and a sharp), b (plus b flat and b sharp), c (flat and sharp), d (flat and sharp), e (flat and sharp), f (flat and sharp), and g (flat and sharp). That makes a, b, c, d, e, f, g Plus the flat and sharp for each, making 21 notes of the scale.
A minor
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.
there is no F# scale on Eb saxaphone....
it has a C sharp but no D natural
There is no difference in terms of each scale would sound, as F-sharp and G-flat are the same exact note. However, when notated on sheet music, they would look different, as the F-sharp scale would use only sharps, and the G-flat scale would use only flats.
D minor - more specifically, D harmonic minor (the version of the minor scale with a flat 6 and a sharp 7). However, you will never see a key signature with a B flat and a C sharp. The key signature will only contain B flat.
UP: d sharp e sharp f sharp g sharp a sharp b sharp c double-sharp d sharp DOWN: d sharp c sharp b natural a sharp g sharp f sharp e sharp d sharp
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.
G sharp (enharmonic A flat).