To test only one condition, <xsl:if></xsl:if> is used.

<xsl:if test="price > 10">
    <tr>
        <td><xsl:value-of select="title"/></td>
        <td><xsl:value-of select="artist"/></td>
    </tr>
</xsl:if>

To express multiple conditional tests you should use a combination of <xsl:choose> and <xsl:when>.

<xsl:choose>
    <xsl:when test="price>'10'">
        <td bgcolor="#ff00ff">
            <xsl:value-of select="artist"/>
        </td>
    </xsl:when>
    <xsl:otherwise>
        <td>
            <xsl:value-of select="artist"/>
        </td>
    </xsl:otherwise>
</xsl:choose>