Sorting by composition title is equally straight-forward
but we have to do it in a separate xsl:apply-templates
element
<xsl:template match="catalog">
<head>
<title><xsl:value-of select="category"/></title>
</head>
<body>
<h1><xsl:value-of select="category"/></h1>
<xsl:apply-templates select="composer">
<xsl:sort select="name/last_name"/>
<xsl:sort select="name/first_name"/>
<xsl:sort select="name/middle_name"/>
</xsl:apply-templates>
<hr/>
Copyright <xsl:value-of select="copyright"/><br/>
Last Modified: <xsl:value-of select="last_updated"/><br/>
<xsl:apply-templates select="maintainer"/>
</body>
</xsl:template>
<xsl:template match="composer">
<h2><xsl:value-of select="name"/></h2>
<xsl:apply-templates select="../composition[@composer=current()/@id]">
<xsl:sort select="title"/>
</xsl:apply-templates>
</xsl:template>