Spotify Apps API - Get the currently playing track (JS)
/* Instantiate the global sp object; include models & views */
var sp = getSpotifyApi(1);
var models = sp.require("sp://import/scripts/api/models");
// Get the track that is currently playing
var currentTrack = models.player.track;
// If nothing currently playing
if (currentTrack == null) {
$('#now-playing').append('No track currently playing');
} else {
var track = currentTrack;
var artist = track.artists[0].name;
$('#now-playing').append("Now playing: " + track, artist);
}