HiddenSounds/_includes/songlist.html

<div class="song">
    <p>
        {%- assign isFirst = true -%}
        {%- for artistName in song.artists -%}
            {%- if isFirst == true -%}
                {%- assign isFirst = false -%}
            {%- else -%}
                , {% comment %} Comma and space to separate artists {% endcomment %}
            {%- endif -%}
            {%- assign artist = site.data.artists | where: 'sname', artistName | first -%}
            {%- if artist -%}
                <a href="{{ artist.sname | datapage_url: 'artists' }}">{{ artist.sname }}</a>
            {%- else -%}
                {{ artistName }}
            {%- endif -%}
        {%- endfor -%}
        {% comment %} Space needed {% endcomment %} - <a href="{{ site.baseurl }}/{{ song.sid | datapage_url: 'songs' }}">{{ song.sname }}</a>
    </p>
</div>