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>