Stash list reverse related

reverse_related_stash_list.html

<!--
 Fill a list, add items to list if a location has an artist
-->

{exp:stash:set_list name="active_locations" 
  parse_tags="yes" parse_depth="2" 
  scope="site" 
  match="#\S#" 
  against="location_artist"
}
    {exp:channel:entries channel="locations" dynamic="off"}
    
        {stash:location_name}{title}{/stash:location_name}
        
        {reverse_related_entries channel="artists" orderby="title" sort="asc"}
            {stash:location_artist}{title}{/stash:location_artist}
            {if no_reverse_related_entries}
                {stash:location_artist}{/stash:location_artist}
            {/if}
        {/reverse_related_entries}
    
    {/exp:channel:entries}
{/exp:stash:set_list}

<!-- output -->

{exp:stash:get_list name="active_locations" scope="site"}
    <h3>{location_name}</h3>
    <p>{location_artist}</p>
{/exp:stash:get_list}