[Dixielandjazz] C# minor as opposed to Db minor

[Robert Smith]

As you've already counted, the key signature for C# minor is four sharps, three #'s less than for C# major (seven #'s), viz. C#, D#, F#, and G#. We have J.S. Bach to thank for the compromise piano (the Well-tempered Clavier), otherwise pianists would have to have two keyboards - one with genuine sharps and one with genuine flats. J.S.'s solution means that everybody plays in the most convenient key, i.e. Db major instead of C# major.
Db major has five flats, and Db minor would therefore have eight flats in order to get over the problem that both A and Ab are in the minor scale. This is done by having Bbb in the scale plus the other six flats. Once again Johan Sebastian has made life easier by making Db minor the same as C# minor.

Quite a few modern composers dispense with key signatures containing sharps or flats. They write everything in C major, and use accidentals to set the mood.

Cheers

Bob