when(optional)Indicates the point of occurrence of this feature along a time line. Its value must
be
the ID of a when element elsewhere in the document.
Value conforms to data.URI.
(MEI.performance) Temporal alignment attributes.
when(optional)Indicates the point of occurrence of this feature along a time line. Its value must
be
the ID of a when element elsewhere in the document.
Value conforms to data.URI.
Performance component declarations.
when(optional)Indicates the point of occurrence of this feature along a time line. Its value must
be
the ID of a when element elsewhere in the document.
Value conforms to data.URI.