Add data from xml to content

I’m trying to connect to last.fm to get artistinfo data directly to my custom post types, it works sometimes, but I have no idea when or how.

I have defined the API in the beginning of the plugin. The problem seems to be when this should be executed.

After I create the title of my custom post type (band) it should add data from last.fm and save to database when I publish it.

function get_lastfm_artistinfo(){
	global $user_ID;
	$my_id = $post->ID;
	$post_id_7 = get_post($my_id);
	$title = $post_id_7->post_title;
//Here is it where it goes wrong, sometimes it works and sometimes it doesn't.
	if(get_post_type() == 'band' && $title != ''){
		$band_link = str_replace('','%20',$title);
		$band = 'http://ws.audioscrobbler.com/2.0/?method=artist.getinfo&artist='.$title.'&api_key='. API_KEY;
		$xml2 = simplexml_load_file($band);
		foreach($xml2->children() as $first){
			$new_post = array(
			'post_title' => $title,
			'post_content' => $first->bio->content,
			'post_status' => 'publish',
			'post_date' => date('Y-m-d H:i:s'),
			'post_author' => $user_ID,
			'post_type' => 'band',
			'post_category' => array(0)
			);
			$post_id = wp_insert_post($new_post);
		}
	}

}
add_filter('the_content', 'get_lastfm_artistinfo');

Does anyone had a similar issue?