$tax_query = array( 'relation' => 'AND', array( 'taxonomy' => 'category', 'terms' => 'spaceflight', 'field' => 'slug', ), array( 'taxonomy' => 'section', 'terms' => 'Opinion', 'field' => 'name', ), array( 'taxonomy' => 'post_format', 'terms' => array( 'post-format-video', 'post-format-audio' ), 'field' => 'slug', 'operator' => 'IN', ), );