The perfDuration element captures the intended duration of the work.
                                 <elementSpec ident="work" module="MEI.header">
                                    
                                    <desc xml:lang="en">Provides a detailed description of a work — a distinct intellectual or artistic creation
                                       —
                                       specifically its history, language use, and high-level musical attributes (
                                       <abbr>e.g.</abbr>, key, tempo,
                                       meter, medium of performance, and intended duration).</desc>
                                    
                                    <classes>
                                       
                                       <memberOf key="att.common"/>
                                       
                                       <memberOf key="att.authorized"/>
                                       
                                       <memberOf key="att.bibl"/>
                                       
                                       <memberOf key="att.dataPointing"/>
                                       
                                       <memberOf key="att.pointing"/>
                                       
                                       <memberOf key="att.targetEval"/>
                                       
                                       <memberOf key="model.workLike"/>
                                       </classes>
                                    
                                    <content>
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       </content>
                                    
                                    <remarks xml:lang="en">
                                       
                                       <p>The <gi scheme="MEI">perfDuration</gi> element captures the <emph>intended duration</emph>
                                          of the work.</p>
                                       </remarks>
                                    </elementSpec>