default-x for <words>

[lemzwerg]

Consider this small MusicXML snippet.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE score-partwise PUBLIC "-//Recordare//DTD MusicXML 4.0 Partwise//EN"
                                "http://www.musicxml.org/dtds/partwise.dtd">
<score-partwise version="4.0">
  <part-list>
    <score-part id="P1"><part-name></part-name></score-part>
  </part-list>
  <part id="P1">
    <measure number="1">
      <attributes><divisions>1</divisions></attributes>
      <direction placement="above">
        <direction-type>
          <words default-x="50" default-y="50">(50,50)</words>
        </direction-type>
      </direction>
      <direction placement="below">
        <direction-type>
          <words default-x="-50" default-y="-150">(-50,-150)</words>
        </direction-type>
      </direction>
      <note>
        <pitch><step>F</step><octave>4</octave></pitch>
        <duration>4</duration>
        <type>whole</type>
      </note>
    </measure>
  </part>
</score-partwise>

Here are the rendering results of Finale and MuseScore:

I've also tested Verovio and SoundSlice. Only Finale honours default-y, while all four programs ignore default-x. Apparently, this sentence from MusicXML's description of default-x,

This attribute provides higher-resolution positioning data than the <offset> element. Applications reading a MusicXML file that can understand both features should generally rely on this attribute for its greater accuracy.

is not popular while importing MusicXML... Interestingly, the files in the musicxml-samples bundle are full with default-x attributes for <words>.

My conclusion is that default-x and default-y are completely unreliable for MusicXML interchange. While this is sort-of acceptable for the vertical axis, it is really problematic IMHO for horizontal positioning of words – users tend to move word items wildly around, probably not taking care of correctly anchoring them to the right notes. Am I correct or am I doing something wrong? Shall I only rely on <offset>?

[Jojo-Schmitz]

Just for the record: this is how MuseScore 2.3.2 renders it:

And this how MuseScore 1.3 does it:

You're right though for 3.6.2 and later, up to 4.5dev

[lemzwerg]

Thanks for the detailed information!

[mdgood]

The <offset> element is indeed generally better for horizontal positioning. It better matches the way many, if not most, notation applications store this information.

[lemzwerg]

Thanks for confirmation.