$re = '/(?:<\d+>)+/m';
$str = '<0><1><2><3><4><5><6><7><8><9><10><11><12><13><14><15><16><17><18>The next 11 keys can change the SWING from OFF (50%) to <19><20><21><22><23 ><24><25>80<26><27><28><29><30><31><32>% during arpeggiator or sequencer operation.<33><34>';
preg_match_all($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