What you could do is, create the "function" as another template file and then include that file passing the parameters to it.
Inside index.html
<h3> Latest Songs </h3>
{% include "song_player_list.html" with songs=latest_songs %}
Inside song_player_list.html
<ul>
{% for song in songs %}
<li>
<div id='songtile'>
<a href='/songs/download/{{song.id}}/'><i class='fa fa-cloud-download'></i> Download</a>
</div>
</li>
{% endfor %}
</ul>