One xml_comment record is created for each comment or processing instruction in a MusicXML file during a conversion from a MusicXML file to a database record using the tasks interface.

The xml_comment table is not part of the MusicXML schema definition. It's an additional feature table that stores comment data so that when a user converts a database record back to a MusicXML file, the content and placement of comments are preserved as in the original file.

Users can optionally select not to include comments in a MusicXML file to database conversion.

For an xml comment, the data field value is the comment string minus the leading <!-- and trailing -->.

For a processing instruction, the data and target values are taken from the Java DOM implementation and are located within the processing instruction as shown below:

<?target data?>

The parent and next_sibling field values indicate the location within an XML document and are taken from XPath. Values are always a fully-specified path with predicates.

next_sibling is null when the comment appears after the last subelement of the parent element.

parent is an empty string when the comment appears before the first element in the file.

Examples:

For a comment in the score header's defaults section, and before the appearance element, the parent and next_sibling field values are:

• parent: /score-partwise[1]/defaults[1]
• next_sibling: appearance[1]

For a comment that occurs at the end of the 3rd part's measure 32:

• parent: /score-partwise[1]/part[3]/measure[32]
• next_sibling: null