[MEI-L] clef as milestone element

[David Lewis]

>> 1. <clef /> is allowed directly in <layer />;
>>
>> As you say below, this,of course , would solve your immediate  
>> problem but
>> what if thinking of multiple layers on one staff; a clef would also  
>> affect
>> the other layers, or am I mistaken? If so it would make no logical  
>> sense as
>> part on a layer; it should be a direct child of staff.
>>
>
> You are right, but that is not very different from <clefchange> that
> is also allowed in a <layer>. When it occurs on all layers at the same
> time, I guess you will put it on all layers. Am I wrong?

I think that this is an important general point about how we read a  
lot of signs in music -- we may take the temporal position of a symbol  
from its position with respect to a single voice (or layer) but  
naturally assume it to apply for all the music found on its staff.  
This is represented as you propose in the music typesetting software I  
contribute to, and I assume in most others. It does require a  
combination of definition (what does it mean to have such a symbol in  
only one layer? what do conflicting symbols mean?) and trust (that the  
encoder has the same definitions and has good error checking), and it  
places some extra load on the interpreting software, but these are  
always the case.

D