Why do we have key signatures as they are? Could a key with unconventional accidentals make sense?
I mean Western music, classical music, circle of fifths and all that. Why can’t I have a key with, for example, three sharps -- though not the usual F, C, and G, but instead some other combination like E, B, and D? I imagine it would sound terribly dissonant. I have heard that the reason there is the conventional progression of sharps/flats (i.e. the circle of fifths) and that there cannot be other strange combinations of sharps/flats is because the keys are “built on each other”. However, I’m not sure what that means exactly.I have a very limited understanding of music theory, and occasionally I have dabbled in (piano) composition and made a few amateur sketches. It is always the case that I find myself “gravitating” toward a certain key in any given attempt. I can never seem to, for example, make a sensible or at least not-terrible-sounding sketch without being in some conventional key, and if I want to introduce anything different I would simply notate accidentals in individual measures (but that would usually only be temporary, e.g. a single one-note dissonance). So what I am wondering is, is it possible to actually compose a solid, structural, perhaps even melodious piece strictly with an unconventional combination of accidentals in the key signature, and where individual measures or segments are *not* in some conventional key signature (which seems to usually be the case, e.g. a piece may be said to be “in C major” but can be in other keys at different moments), which would usually achieved by introducing accidentals? (I mean, one could put B as the only sharp in the key signature, but then simply add a natural to each B throughout the piece… so effectively it’s just C major.)Could a key with unconventional accidentals make sound, structural, perhaps even harmonic and melodic sense... a key that is perhaps separate and distinct from the conventional key signatures, and maybe even with a different "quality", "temperament", or "feel"?