In order to do that, you will have revert the previous change and edit the file components/com_hikashop/views/product/view.html.php and change the code:
$query = "SELECT category_id FROM ".hikashop::table('product_category').' WHERE product_id='.$product_id.' ORDER BY ordering';
to the code:
//load products in the same first category
$query = "SELECT category_id FROM ".hikashop::table('product_category').' WHERE product_id='.$product_id.' ORDER BY product_category_id ASC LIMIT 1';
And, for all your products, the first category you add to it should be the artist category. If it's always the last, then, you should replace ASC by DESC.