Applying a lightbox to images from API

$(document).ready(function() {

    $('form').submit(function(evt) {

        evt.preventDefault();

        // var $searchField = $('#song');

        var spotifyAPI = "https://api.spotify.com/v1/search" // needs end point

        // var albums = $searchField.val();// Specifies type of user info to be retrieved and sent to Spotify API

        var spotifyOptions = {

            "type": "album",

            "query": $("#song").val(),

            "limit": "12"


        }; // Requests data from spotify API. Must be a JavaScript Object
        $.getJSON(spotifyAPI, spotifyOptions, displayAlbums); // Currently, these are only placeholders. The variables inserted as arguments have not been defined as variables
        function displayAlbums(data){
            var albumHTML = '<ul>'; // Opening ul tag to hold a single album result
            $.each(data.albums.items, function(i, album){
                albumHTML += '<div class="album col-md-3" album-id="' + album.index + '">';
                albumHTML += '<li>'; // You may need to use bootstrap to style array items correctly
                albumHTML += '<a href="#">';
                albumHTML += '<img src="' + album.images[0].url + '" alt="' + album.artists.name + '">';
                albumHTML += '</a>';
                albumHTML += '</li>';
                albumHTML += '</div>';
                return albumHTML;
            });

                albumHTML += '</ul>';
                $('#music').html(albumHTML);

            }; 

// supposed to be the lightbox

            var $overlay = $('<div id="overlay"></div>');
            var $image = $("<img>");
        var $caption = $("<p></p>");            

            $overlay.append($image);
            $overlay.append($caption);

            $("body").append($overlay);

            $("#song a").click(function(event){
                event.preventDefault();
                var imageLocation = $(this).attr("src"); // May need to specify a second argument
                $image.attr("src", imageLocation);
                $overlay.show();

                var captionText = $(this).children(img).attr("alt");
                $caption.text(captionText);
            }); 

            $overlay.click(function(){
                $overlay.hide();

            });

        });

    });