Transposition: Prevent double accidentals in chord symbols

[bryantgeorge]

Is there any way of preventing double accidentals when transposing chord symbols with verovio (for example, Ebb -> D)?

[lpugin]

Please add an example file and list the exact options you use for the transposition.

[bryantgeorge]

Granted the chord symbols in this file are probably ridiculous, but a musicxml file like this with --transpose Db for example:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE score-partwise PUBLIC "-//Recordare//DTD MusicXML 3.1 Partwise//EN" "http://www.musicxml.org/dtds/partwise.dtd">
<score-partwise version="3.1">
  <identification>
    <encoding>
      <software>MuseScore 3.6.2</software>
      <encoding-date>2022-09-21</encoding-date>
      <supports element="accidental" type="yes"/>
      <supports element="beam" type="yes"/>
      <supports element="print" attribute="new-page" type="yes" value="yes"/>
      <supports element="print" attribute="new-system" type="yes" value="yes"/>
      <supports element="stem" type="yes"/>
      </encoding>
    </identification>
  <defaults>
    <scaling>
      <millimeters>6.432</millimeters>
      <tenths>40</tenths>
      </scaling>
    <page-layout>
      <page-height>1737.13</page-height>
      <page-width>1342.48</page-width>
      <page-margins type="both">
        <left-margin>157.4</left-margin>
        <right-margin>157.4</right-margin>
        <top-margin>78.7313</top-margin>
        <bottom-margin>78.7313</bottom-margin>
        </page-margins>
      </page-layout>
    <word-font font-family="Edwin" font-size="10.25"/>
    <lyric-font font-family="Edwin" font-size="10.25"/>
    </defaults>
  <part-list>
    <score-part id="P1">
      <part-name></part-name>
      <score-instrument id="P1-I1">
        <instrument-name>Women</instrument-name>
        </score-instrument>
      <midi-device id="P1-I1" port="1"></midi-device>
      <midi-instrument id="P1-I1">
        <midi-channel>1</midi-channel>
        <midi-program>53</midi-program>
        <volume>78.7402</volume>
        <pan>0</pan>
        </midi-instrument>
      </score-part>
    <score-part id="P2">
      <part-name></part-name>
      <score-instrument id="P2-I1">
        <instrument-name>Men</instrument-name>
        </score-instrument>
      <midi-device id="P2-I1" port="1"></midi-device>
      <midi-instrument id="P2-I1">
        <midi-channel>4</midi-channel>
        <midi-program>53</midi-program>
        <volume>78.7402</volume>
        <pan>0</pan>
        </midi-instrument>
      </score-part>
    </part-list>
  <part id="P1">
    <measure number="1" width="977.68">
      <print>
        <system-layout>
          <system-margins>
            <left-margin>50.00</left-margin>
            <right-margin>-0.00</right-margin>
            </system-margins>
          <top-system-distance>170.00</top-system-distance>
          </system-layout>
        </print>
      <attributes>
        <divisions>1</divisions>
        <key>
          <fifths>0</fifths>
          </key>
        <time>
          <beats>4</beats>
          <beat-type>4</beat-type>
          </time>
        <clef>
          <sign>G</sign>
          <line>2</line>
          </clef>
        </attributes>
      <harmony print-frame="no">
        <root>
          <root-step>C</root-step>
          </root>
        <kind>major</kind>
        </harmony>
      <note default-x="83.49" default-y="-20.00">
        <pitch>
          <step>B</step>
          <octave>4</octave>
          </pitch>
        <duration>1</duration>
        <voice>1</voice>
        <type>quarter</type>
        <stem>down</stem>
        <lyric number="1" default-x="6.50" default-y="-46.99" relative-y="-30.00">
          <syllabic>single</syllabic>
          <text>This</text>
          </lyric>
        </note>
      <harmony print-frame="no">
        <root>
          <root-step>F</root-step>
          <root-alter>1</root-alter>
          </root>
        <kind>major</kind>
        <bass>
          <bass-step>D</bass-step>
          <bass-alter>-1</bass-alter>
          </bass>
        </harmony>
      <note default-x="304.37" default-y="-20.00">
        <pitch>
          <step>B</step>
          <octave>4</octave>
          </pitch>
        <duration>1</duration>
        <voice>1</voice>
        <type>quarter</type>
        <stem>down</stem>
        <lyric number="1" default-x="6.50" default-y="-46.99" relative-y="-30.00">
          <syllabic>single</syllabic>
          <text>is</text>
          </lyric>
        </note>
      <harmony print-frame="no">
        <root>
          <root-step>A</root-step>
          <root-alter>-1</root-alter>
          </root>
        <kind>major</kind>
        </harmony>
      <note default-x="525.26" default-y="-20.00">
        <pitch>
          <step>B</step>
          <octave>4</octave>
          </pitch>
        <duration>1</duration>
        <voice>1</voice>
        <type>quarter</type>
        <stem>down</stem>
        <lyric number="1" default-x="6.50" default-y="-46.99" relative-y="-30.00">
          <syllabic>single</syllabic>
          <text>a</text>
          </lyric>
        </note>
      <harmony print-frame="no">
        <root>
          <root-step>B</root-step>
          <root-alter>-1</root-alter>
          </root>
        <kind>major</kind>
        </harmony>
      <note default-x="746.14" default-y="-20.00">
        <pitch>
          <step>B</step>
          <octave>4</octave>
          </pitch>
        <duration>1</duration>
        <voice>1</voice>
        <type>quarter</type>
        <stem>down</stem>
        <lyric number="1" default-x="6.50" default-y="-46.99" relative-y="-30.00">
          <syllabic>single</syllabic>
          <text>song</text>
          </lyric>
        </note>
      <barline location="right">
        <bar-style>light-heavy</bar-style>
        </barline>
      </measure>
    </part>
  <part id="P2">
    <measure number="1" width="977.68">
      <print>
        <staff-layout number="1">
          <staff-distance>66.72</staff-distance>
          </staff-layout>
        </print>
      <attributes>
        <divisions>1</divisions>
        <key>
          <fifths>0</fifths>
          </key>
        <time>
          <beats>4</beats>
          <beat-type>4</beat-type>
          </time>
        <clef>
          <sign>F</sign>
          <line>4</line>
          </clef>
        </attributes>
      <note default-x="83.49" default-y="-126.72">
        <pitch>
          <step>D</step>
          <octave>3</octave>
          </pitch>
        <duration>1</duration>
        <voice>1</voice>
        <type>quarter</type>
        <stem>down</stem>
        </note>
      <note default-x="304.37" default-y="-126.72">
        <pitch>
          <step>D</step>
          <octave>3</octave>
          </pitch>
        <duration>1</duration>
        <voice>1</voice>
        <type>quarter</type>
        <stem>down</stem>
        </note>
      <note default-x="525.26" default-y="-126.72">
        <pitch>
          <step>D</step>
          <octave>3</octave>
          </pitch>
        <duration>1</duration>
        <voice>1</voice>
        <type>quarter</type>
        <stem>down</stem>
        </note>
      <note default-x="746.14" default-y="-126.72">
        <pitch>
          <step>D</step>
          <octave>3</octave>
          </pitch>
        <duration>1</duration>
        <voice>1</voice>
        <type>quarter</type>
        <stem>down</stem>
        </note>
      <barline location="right">
        <bar-style>light-heavy</bar-style>
        </barline>
      </measure>
    </part>
  </score-partwise>

[craigsapp]

If you are transposing to D-flat major, then the double flats are correct, although I am getting a funny Korean character on my macos computer at the moment instead of double-flats.

So it would not be appropriate for the spelling change to happen by default. For best control of the results you should apply the enharmonic spelling yourself after transposing. This could be done with XSLT for example.

If this is done in verovio, there are two possible methods:

(1) Automatically: If you transpose using --transpose 1 rather than --transpose Df or --transpose Db, you are already not concerned about whether C-sharp or D-flat key signature will be used. The numeric transposition process could also trigger an automatic enharmonic respelling of the chord names (and for double sharp/flat notes in the music).

(2) Manually: add an option that would enharmonically respell any double/triple sharps/flats to a single-accidental (or natural) equivalent. The option name could be something like --transpose-enharmonic-simplify. This would apply both to the chord labels and to the notes.

In your example (untransposed in C major):

What does F#/Db mean? In standard chord notation this is notating an inversion of the F-sharp chord, with D-flat as the lowest sounding note. There is no D-flat in an F-sharp chord, so I am wondering why it is not labeled F#/C#? Spelling it correctly will avoid the problem with the provided test case... A more realistic case would be useful to determine the best method of the three possibilities listed above to use.

[bryantgeorge]

Thanks for the reply! I think I was just misunderstanding how transposition should work (ie. the double accidentals seem to be correct musically). As a secondary question though, the documentation shows a --transpose-selected-only option that I haven't been able to figure out. Would this option make it possible to, for example, transpose only certain select chord symbols in a score?

[lpugin]

The scope for --transpose-selected-only is mdiv. By default, Verovio loads a single mdiv, which can be chosen with --mdiv-x-path-query. However, by default, all of them are transposed. By setting --transpose-selected-only, only the selected mdiv will be transposed.

I updated the documentation, which hopefully makes it clearer.

[bryantgeorge]

Got it, thanks.