How to get multiple Taxonomies not All Taxonomies?

I believe your error is in the if ( $taxonomies ) statement, I believe you want if ( is_taxonomy( $taxonomy ); ) see this link for further usages.

I’m not at home so I can’t test this, but I think the option you present should work, as mentioned here.

$args = array( 
 'name' => array( 'actors', 'directors', 'musicians' )
);

And I think you should also remove the . from $content .= ''; making it $content="";, this error repeats itself 3x.

I would also like to know, when you use the code $args = array( 'name' => 'actors'); does the code perform as intended?