$re = '/(?x)
^
([^-]+) # Capture everything not a dash
\s+-\s+ # Match white space(s) dash white space(s)
((?1)) # Capture everything not a dash
\.mp3
$
/m';
$str = 'My Test Name - h1n.mp3
Arist of Song - Title of song.mp3';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php