Why Two Names for the "Same" Key?I am often asked why there must be fifteen keys in music instead of twelve—that is, why not always write in B instead of C-flat, in F-sharp instead of G-flat, in D-flat instead of C-sharp, orvice versa? I can only say that the circle of fifths would not be complete without the seven scales in sharps and the seven in flats: but Bach does not use all the fifteen keys in his Forty-eight Preludes and Fugues, omitting entirely, in the major keys, G-flat, D-flat, and C-flat, and, in the minor keys, A-sharp and A-flat. Are compositions in sharps considered more brilliant than those in flats? Do composers consider modulation in selecting their key?The answer to your question hinges upon whether you recognize in music mere tone-play or whether you concede a mental and psychic side to it. In the former case the mode of spelling a tone C-sharp or D-flat would be, indeed, irrelevant. But in the latter case you must admit the necessity of a musicalorthography qualified to convey distinct tonal meanings and musical thoughts to the reader and to the player. Though there is in the tempered scale no difference between C-sharp and D-flat, the musical reader will conceive them as different from one another, partly because of their connection with other related harmonies. These determine usually the composer's selection in cases of enharmonic identities. In the script of human language you will find an analogy than which none could be more perfect. In English there are, for instance, "to," "too," and "two"; words in which the spelling alone, and not the sound of pronunciation, conveys the different meanings of the words.
Why Two Names for the "Same" Key?
I am often asked why there must be fifteen keys in music instead of twelve—that is, why not always write in B instead of C-flat, in F-sharp instead of G-flat, in D-flat instead of C-sharp, orvice versa? I can only say that the circle of fifths would not be complete without the seven scales in sharps and the seven in flats: but Bach does not use all the fifteen keys in his Forty-eight Preludes and Fugues, omitting entirely, in the major keys, G-flat, D-flat, and C-flat, and, in the minor keys, A-sharp and A-flat. Are compositions in sharps considered more brilliant than those in flats? Do composers consider modulation in selecting their key?
The answer to your question hinges upon whether you recognize in music mere tone-play or whether you concede a mental and psychic side to it. In the former case the mode of spelling a tone C-sharp or D-flat would be, indeed, irrelevant. But in the latter case you must admit the necessity of a musicalorthography qualified to convey distinct tonal meanings and musical thoughts to the reader and to the player. Though there is in the tempered scale no difference between C-sharp and D-flat, the musical reader will conceive them as different from one another, partly because of their connection with other related harmonies. These determine usually the composer's selection in cases of enharmonic identities. In the script of human language you will find an analogy than which none could be more perfect. In English there are, for instance, "to," "too," and "two"; words in which the spelling alone, and not the sound of pronunciation, conveys the different meanings of the words.