Дмитрий

setTimer(1, 10);

function setTimer(c, f){
	document.querySelector('#timer').innerHTML = c;
  if(c < f)setTimeout(setTimer, 1000, c + 1, f);
}

setTimer(1, 10,  function(){alert('finished')});

function setTimer(c, f, callback){
	document.querySelector('#timer').innerHTML = c;
  if(c < f)setTimeout(setTimer, 1000, c + 1, f, callback);
  else if(callback)callback();
}

function getCounter() {
  var start = 1;
  var stop = 10;
  return function() {
  start++;
  if(start != stop) setTimeout(arguments.callee, 1000);
}
setTimeout(getCounter(), 1000);

foreach ($arr as $arr) {
    foreach ($arr['repertuar__block'] as $out) {
        echo $out['repertuar__video__url'] . " и " . $out['repertuar__preview'] . "<hr>";
    }
}

$preview = [];
foreach ($arr as $arr_item) {
  if ( !is_empty($arr_item['repertuar__block']) ) {
    foreach ($arr_item['repertuar__block'] as $arr_i) {	
          $preview[] = $arr_i["repertuar__preview"];  
    }
  }
}
print_r($preview);

<?php  
$arr = array(1) { 
  [0]=> array(5) {
    ["tab__button"]=> string(16) "Top Hits, 2000-e" 
    ["repertuar__readmore__text"]=> string(48) "/Смотреть другие концерты/" 
    ["repertuar__readmore__link"]=> string(33) "/cntnt/nas_vybira/nastoyashe.html" 
    ["repertuar__block"]=> array(1) { 
                  [0]=> array(2) { 
                      ["repertuar__video__url"]=> string(199) "url" 
                      ["repertuar__preview"]=> string(76) "http://www./hqdefault.jpg"
  } 
}
?>