I often wonder why when music notation was being developed nobody thought of putting two ledger lines between the staves of the Grand Staff, for instance middle c and then e a major 3rd above, or the a below middle c and middle c. This would keep the same note names for the lines and spaces for the two staves (or any number of staves). All you would need then was a clef to tell you what octave you were playing in.
Cheers,
Dennis
Cheers,
Dennis