BartK All these notational reforms seem to be either invented by beginners or aimed at beginners for a perceived convenience or simplicity, whereas the notational system that is currently in widespread use was invented by and for the convenience of professional musicians.
Many great and good inventions have been made by beginners. The beginners, that were learning the existing system and figured out some flaws. The people you describe as "professional musicians" simply didn't see the shortcomings. Or they got used to the existing one, and they don't see a need to change it. And sure, why should they change something they have become a master of?
I think it was Mark Twain who said something like this: "If one does something always the same way and never thought about changing it, it is likely he did it in a bad way, all the time."
BartK The first problem with a double-G clef or double-F clef notation is the range. The bass C on the image above is the C that normally sits on the second space from the bottom of the staff. That means you need a lot more legder lines than normally used to reach the lower notes.
True, BUT you would get rid of one ledger line on top of the upper staff. And if I overfly my sheet music, I see a lot more ledger lines on top of the treble clef compared to the bottom of it. Result: a big win in terms of range for double F-clef. Hands down.
BartK The double-F clef would be even worse for range because to reach the top note you would need to use both a 15 on the clef and a 15ma notation above the staff, and you would still need ledger lines.
Please, Bart, don't play the "pretend to be stupid"-game. Or course there needs to be a different clef symbol that indicates the octave range. Someone can invent new fancy symbols or just go with the approach of Referend Thomas Salmon from 1672, to use "Tr", "M" and "B" as clef symbols.
BartK Speaking of intervallic relationships, the second problem I see with this is around the middle. The ledger lines in between the staves preserve all the intervallic relationships between the hands because middle C is the same line above and below. If you have notes going up several ledger lines from the bass staff you know how they relate to the notes in the right hand, and vice versa. This is not so clear when the top note is F and the spaces and lines are inverted when going further up.
Come on, we both know this would be the same with two F-clefs. Except it isn't the middle C in the very center, but the middle D instead.
BartK As a beginner you might not encounter music that has these issues and it might seem simpler at first but that kind of puts a limit on your development.
And again, the "you are a beginner"-card. I might be a beginner, still I understand enough to defend my points with ease.
BartK As a more advanced pianist I can assure you that the way I think about the music when I look at notation is very different than what it used to be as a beginner.
You can assure me. But you failed every time when you tried to point it out.
BartK Most of the time I don't really care about what the actual notes are (although I learned to recognise all the note and it didn't really take very long and I don't get all the fuss about having to learn it)...
Then you wouldn't care as well, if you learned it differently?
BartK ...but I care a lot about intervals and shapes of chords.
Good point. But this would not change. You can recognize the intervals and shapes of chords as you can today.
BartK If I see a big chord that has a top note something like 5 ledger lines above the staff I don't even count those lines because normally I see chord shapes.
Whoa - one ledger line less. Would this really be a problem for you? Do you really think it gets harder because of that?