Historically, the term "slur" indicated two notes performed legato, while the term "phrase" was used for a "unified melodic idea". Nowadays, however, "slur" often has the same meaning as "phrase" (See Read, p. 265-266), since the visual rendition of the two concepts is the same. MEI provides two distinct elements so that those users wishing to maintain a distinction for historical reasons may do so. If the user does not want to maintain the distinction, then the more generic <slur> element should be employed. The starting point of the phrase/slur may be indicated by either a @startid, @tstamp, @tstamp.ges, or @tstamp.real attribute, while the ending point may be recorded by either a @dur, @dur.ges, @endid, or @tstamp2 attribute. It is a semantic error not to specify one starting and one ending type of attribute. Either @place, @bulge, or @bezier attributes may be used to record the curvature of the phrase/slur. The <slur> and <tie> elements may be used instead of the slur.* and tie.* attributes provided on <chord> and <note> elements when 1) they are required by software, or 2) multiple, alternative slurs are needed.
<elementSpec ident="slur" module="MEI.cmn">
<desc xml:lang="en">Indication of 1) a "unified melodic idea" or 2) performance technique.</desc>
<classes>
<memberOf key="att.common"/>
<memberOf key="att.facsimile"/>
<memberOf key="att.slur.log"/>
<memberOf key="att.slur.vis"/>
<memberOf key="att.slur.ges"/>
<memberOf key="att.slur.anl"/>
<memberOf key="model.controlEventLike.cmn"/>
</classes>
<constraintSpec ident="slur_start-_and_end-type_attributes_required" scheme="schematron">
<constraint>
<sch:rule context="mei:slur">
<sch:assert test="@startid or @tstamp or @tstamp.ges or @tstamp.real">Must have one of the
attributes: startid, tstamp, tstamp.ges or tstamp.real.</sch:assert>
<sch:assert test="@dur or @dur.ges or @endid or @tstamp2">Must have one of the attributes:
dur, dur.ges, endid, or tstamp2.</sch:assert>
</sch:rule>
</constraint>
</constraintSpec>
<constraintSpec ident="slur_containing_curve" scheme="schematron">
<constraint>
<sch:rule context="mei:slur[mei:curve[@bezier or @bulge or @curvedir or @lform or @lwidth or @ho or
@startho or @endho or @to or @startto or @endto or @vo or @startvo or @endvo or @x
or @y or @x2 or @y2]]">
<sch:assert test="not(@bezier or @bulge or @curvedir or @lform or @lwidth or @ho or @startho or @endho
or @to or @startto or @endto or @vo or @startvo or @endvo or @x or @y or @x2 or @y2)" role="warning">The visual attributes of the slur (@bezier, @bulge, @curvedir, @lform,
@lwidth, @ho, @startho, @endho, @to, @startto, @endto, @vo, @startvo, @endvo, @x,
@y,
@x2, and @y2) will be overridden by visual attributes of the contained curve
elements.</sch:assert>
</sch:rule>
</constraint>
</constraintSpec>
<remarks xml:lang="en">
<p>Historically, the term "slur" indicated two notes performed legato, while the term
"phrase"
was used for a "unified melodic idea". Nowadays, however, "slur" often has the same
meaning
as "phrase" (See Read, p. 265-266), since the visual rendition of the two concepts
is the
same. MEI provides two distinct elements so that those users wishing to maintain a
distinction for historical reasons may do so. If the user does not want to maintain
the
distinction, then the more generic <gi scheme="MEI">slur</gi> element should be employed.
The starting point of the phrase/slur may be indicated by either a <att>startid</att>,
<att>tstamp</att>, <att>tstamp.ges</att>, or <att>tstamp.real</att> attribute, while the
ending point may be recorded by either a <att>dur</att>, <att>dur.ges</att>,
<att>endid</att>, or <att>tstamp2</att> attribute. It is a semantic error not to specify one
starting and one ending type of attribute. Either <att>place</att>, <att>bulge</att>, or
<att>bezier</att> attributes may be used to record the curvature of the phrase/slur. The <gi scheme="MEI">slur</gi> and <gi scheme="MEI">tie</gi> elements may be used instead of the
slur.* and tie.* attributes provided on <gi scheme="MEI">chord</gi> and <gi scheme="MEI">note</gi> elements when 1) they are required by software, or 2) multiple, alternative slurs
are needed.</p>
</remarks>
</elementSpec>