$re = '~^(?P<artist>.+?(?=\s-\s)) # artist with pos. lookahead
\s-\s # space - space
(?P<title>.+?(?=(?:\(?Feat\.)|$)) # title with pos. lookahead
\(? # optional open parenthesis
(?P<artist2>Feat\.[^()\n]+)? # artist2 with Feat. before
\)? # optional closing parenthesis
(?P<subtitle>.+)?$ # optional subtitle~mx';
$str = 'Black Coast - Trndsttr
Black Coast - Trndsttr (Feather)
Black Coast - Trndsttr (Lucian Remix)
Black Coast - Trndsttr (Feather) (Lucian Remix)
Black Coast - Trndsttr Feat. M. Maggie
Black Coast - Trndsttr (Feat. M. Maggie)
Black Coast - Trndsttr Feat. M. Maggie (Lucian Remix)
Black Coast - Trndsttr (Feat. M. Maggie) (Lucian Remix)
Black Coast - Trndsttr (Lucian Remix) Feat. M. Maggie
Black Coast - Trndsttr (Lucian Remix) (Feat. M. Maggie)
Black Coast - Trndsttr (Feather) (Lucian Remix) Feat. M. Maggie
Black Coast - Trndsttr (Feather) (Lucian Remix) (Feat. M. Maggie)
Black Coast - Trndsttr (Feather) Feat. M. Maggie (Lucian Remix)
Black Coast - Trndsttr (Feather) (Feat. M. Maggie) (Lucian Remix)
Black Coast - Trndsttr (Feather) (Feat. M. Maggie) Lucian Remix
Black Coast - Trndsttr (Feather) Feat. M. Maggie Lucian Remix
';
$subst = "$1 $3 - $2$4";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
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