Re: Does the center of the staff need to be zero?

[Juergen Reuter]

On Mon, 19 Mar 2007, Kevin Dalley wrote:

> ...
> The G clef is correct, if you change your interpretation a bit.  It
> confused me for quite a while also.  The documentation needs to be
> improved, but I haven't figured out exactly how.
>
> The G-clef is centered around the G note.  The center of the staff at
> B above middle C, however many lines there are.
>
> So a 4-line G-clef leaves the G-clef centered around a space,
> rather than around a bar.
>
> If you typeset a G note, it will be in the same position on the G
> clef.

You are right, but this is not the issue I was trying to point out.  The 
problem is neither of musical nor notational kind, but of typographical 
kind.  Maybe I should have chosen the bass clef as a more evident example:

If you reduce the number of stafflines to 4, the bass clef will always be 
set in such a way, that the two dots of the bass clef glyph collide with 
the stafflines.  The problem is, that the typograhical design of the bass 
clef assumes that the f pitch (the f which the bass clef references) is 
always typeset on a staffline, but not in the space between two 
stafflines, such that the bass clef's two dots are always printed between 
stafflines.  Similar typographical aspects hold for other clefs.

If the y origin of a staff would always be on, say, the lowest staffline 
rather than on the center of the staff, then the bass clef would be 
aligned correctly even on a staff with 4 stafflines.

> \new Staff \with {
>  middleCPosition = #-2
>  clefGlyph = #"clefs.G"
>  clefPosition = #2
> }

No, unfortunately, the clefPosition property does not help here at all, 
since it shifts the clef by an integer multiple of staffline space, while, 
in the case of an even number of stafflines, it would need to be shifted 
by an odd integer multiple of half a staffline space.

In other words, a clef is typographical designed to be always aligned with 
a staffline, but not to be aligned with the space between two stafflines. 
The only exception that I know of is the drum clef, which is typically 
always centered, regardless of the number of stafflines.

Greetings,
Juergen