Re: MNX proposal §1.2

Hi James,

I realize that this note is unlikely to change your mind or your direction,
but I would like to briefly correct a few mistaken impressions that I hope
others do not take away.

The problem with MusicXML is that it was designed for sheet music, and
> sheet music contains purely spatial information. Temporal info is inferred
> from the graphics, but that is a mistake. Any temporal info associated with
> sheet music is stored in living traditions of performance practice, not on
> the page. Metronome marks are just a way to transfer temporal info into a
> performer's memory.
>

Sheet music in any well-known notational idiom (CWMN being just one) is
spatial information that refers to *a shared understanding* of the living
tradition of performance practice. As such, it is semantic information:
there are underlying concepts that we all recognize as referred to by the
same marks, regardless of their geometric details.

Consider this analogous to the fact that the marks you are now reading
refer to *a shared understanding* of the living tradition of the English
language. Thus, we do not consider an ordinary, textual book -- or an
email, like this one -- to be "purely spatial information".


> MNX describes computer files that are not restricted to spatial
> information in this way. Spatial and temporal info can be stored in the
> same file. So, when migrating MusicXML files, MNX has to be explicit about
> the type of the information it is describing. Is it spatial or temporal?
>

You are leaving out the main dish: it is semantic, and not spatial or
temporal.

All of the elements in MNX that you critique as being spatial -- <tempo>,
<event>, and so forth -- are semantic in nature. They encode the *shared
understanding* of the symbol. And this is only possible by restricting the
language to a specific universe of understandings; in this case, CWMN.
Without such a restriction, one may adopt a purely spatial approach for
encoding music, in which case SVG is a reasonable vehicle. But that would
fail to address many of our main use cases.

For this reason we've left room to encode purely graphical scores by
embedding them within MNX. I believe there are multiple approaches to
connecting SVG to MIDI (and other audio formats) that may be better to the
one that you've proposed, and I am in the process of pulling in some other
W3C folks whose expertise is very relevant to this discussion. More on that
soon.


> What the symbol* means *is temporal information that should be supplied
> separately.
>

Actually, in MNX both the spatial and the temporal information are supplied
separately from semantic information. Please see:

https://w3c.github.io/mnx/overview/#styling
https://w3c.github.io/mnx/overview/#interpretation

In the interests of brevity, I will leave it here.

...Joe