set sub page for post type archive - wordpress

[admin]

<ol>
<li>I have <strong>songs</strong> post type</li>
<li>I have <strong>songs</strong> page : (i made page in wordpress panel) <a href="http://nabzetaraneh.ir/songs/" rel="nofollow">http://nabzetaraneh.ir/songs/</a></li>
<li>I have a page called <strong>the_tops</strong> : <a href="http://nabzetaraneh.ir/songs/the_tops/" rel="nofollow">http://nabzetaraneh.ir/songs/the_tops/</a></li>
</ol>

<strong>the_tops</strong> parent is <strong>songs</strong>

but you can see 404

<blockquote>
permalinks on /%postname%/
</blockquote>