MusicXML documentation clarifications for halign, justify and valign

Please post this as an issue for updating the MusicXML documentation:

The documentation for halign, valign and justify needs to be clarified and made more comprehensive.

In particular, there needs to be an explanation of what is meant to happen in each of the four possible combinations of the presence or absence of halign and justify - what the default behavior is, what overrides may occur, etc.  In addition, examples showing combinations of all of the possible values of halign and justify together would be helpful.  Finally, it would be nice to clarify exactly what is meant by “left”, “center” and “right”..  For example, do they refer to positions relative to page margins?  Does that include system margins?  What happens to “center” if left and right margins are not equal? And so on.  A picture might be worth a thousand words.

For valign, the documentation should be made absolutely clear with respect to the references used for vertical positioning of text.  In particular, “center” should specify that it means “half the distance from the baseline to the top of the ascent”, or something similar, “top” should specify that it means “the ascent distance from the baseline”, and “bottom” should be specified as “the descent distance from the baseline”. 

Thanks.

Best regards,

Evan Brooks

Received on Wednesday, 23 March 2016 20:02:43 UTC