WordPress: Order Custom Taxonomy Term page by custom key

order taxonomy

/**
 * Make sure to order staff on role term pages alphabetically by last name
 *
 * @author      Jon Breitenbucher <jbreitenbucher@wooster.edu>
 * @version     SVN: $Id$
 * @param       array $query Default query arguments
 * @return      array modified query arguments
 *
 * @since       2.0
 *
 */

function tech_staff_alpha_order_posts( $query) {

    if ( $query->is_main_query() && !is_admin() && is_tax( 'taxonomy' ) ) {
        $query->set( 'meta_key', 'it_last_name_text' );
        $query->set( 'orderby', 'meta_value' );
        $query->set( 'order', 'ASC' );
        return $query;
    }
}
add_action('pre_get_posts', 'tech_staff_alpha_order_posts');