Measure-free scores

In the scope of the profile <score content="cwmn" profile="standard"> there
are measure-free scores. The typical examples are many pieces from Erik
Satie.

It has been suggested that for regularity of the schema, measure-free
scores or passages be treated as consisting of either a single big measure
or of smaller measures with hidden barlines and time signatures.

Two ideas on this:

1. In my opinion the MNX standard must choose between using a single big
measure or using smaller measures with hidden barlines and time signature.
One of the MNX objectives is to enforce programs to create semantically
correct MNX files. Leaving the decision on how to encode measure-free
scores to each MNX writer/exporter will provide unnecessary freedom and
this will introducing unnecessary complexity in MNX parsers and could
create unexpected future problems.

2. Although a 'hidden' attribute attached to an element can be useful for a
particular application, I dislike the idea of describing the semantics
using hidden objects. The attribute 'hidden' has to do with appearance, not
with semantics and, therefore, the objects composing the music score should
be described in MNX without having to resort on appearance attributes.

Therefore, my suggestion is to treat CWMN measure-free scores as consisting
of a single big measure, somehow marked as 'structural' to distinguish
these structural measures from regular ones, i.e. to treat the structural
ones as 'hidden'  ;-)

Cecilio