How to create a list of terms who’s posts also have a predefined external term?

if i understand correctly you want to get a list of albums (posts) of a specific artist(taxonomy) and that are have ihaveit term.

if so the its a simple query using tax_query:

$args = array(
    'posts_per_page' => -1, //get all
    'post_type' => 'album', 
    'tax_query' => array(
        'relation' => 'AND',
        array(
            'taxonomy' => 'artist',
            'field' => 'slug', 
            'terms' => array( 'artist-slug' )
        ),
        array(
            'taxonomy' => 'whereisit',
            'field' => 'slug',
            'terms' => array('ihaveit')
        )
    )
);
$query = new WP_Query( $args );
while($query->have_posts())
{
    $query->the_post();
    //to your thing / loop here
}