Split on linebreaks and a delimiter on each line.

linebreaksplit.php

<?php
$thestring =<<< EOS
The beats: fast
The rhymes: bold
The brass: monkey
EOS;
 
// If this doesn't work, try the pattern /$\R?^/m
// Yes, that's the endline before the startline.
foreach(preg_split("/\r\n|\n|\r/", $thestring) as $line){
$linearray = explode(':', $line);
echo '<b>' . $linearray[0] . '</b>: ' . $linearray[1] . '<br />';
}
?>