I built a popup using this article and it looks really good.
Here is what I did:
You have to remove the Vimeo content thus stopping the audio completely. If not that, you would have to use Vimeo API to stop/pause/play the video.
Here a demonstration of how it can be done, adding an iFrame as HTML content for #popup-box .popup-content
and then setting the HTML to an empty string to remove it.
(function($) {
$(document).ready(function(){
var iframe = '<iframe src="https://player.vimeo.com/video/213100067?title=0&byline=0&portrait=0&badge=0" width="640" height="360" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>';
// When the user clicks on the button, open the modal
$("#open-popup").on('click', function(e) {
e.preventDefault();
$('#popup-box').show();
$('#popup-box .popup-content').html(iframe);
});
// When the user clicks on <span> (x), close the modal
$('#popup-box .close, #popup-box').on('click', function() {
$('#popup-box').hide();
$('#popup-box .popup-content').html('');
});
});
})(jQuery);
/* The Modal (background) */
.modal {
display:none;
position: fixed; /* Stay in place */
z-index: 1; /* Sit on top */
left: 0;
top: 0;
width: 100%; /* Full width */
height: 100%; /* Full height */
overflow: auto; /* Enable scroll if needed */
background-color: rgb(0,0,0); /* Fallback color */
background-color: rgba(0,0,0,0.4); /* Black w/ opacity */
}
/* Modal Content/Box */
.popup-content {
background-color: #fefefe;
margin: 15% auto; /* 15% from the top and centered */
padding: 20px;
border: 1px solid #888;
width: 80%; /* Could be more or less, depending on screen size */
}
/* The Close Button */
.close {
color: #aaa;
float: right;
font-size: 28px;
font-weight: bold;
}
.close:hover,
.close:focus {
color: black;
text-decoration: none;
cursor: pointer;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button id="open-popup">Play</button>
<div id="popup-box" class="modal">
<span class="close">×</span>
<div class="popup-content">
</div>
</div>