If you want to get an updated list of the top 100 tracks in Billboard Charts from different music genres, you must have this app installed on your iOS device.
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Billboard and Spotify When you tap on the icon with the label "Spotify", the Spotify app will open and the track will be played directly on the app. If you are subscribed to Spotify Premium, you can keep the track for offline playing. In that sense, even if you didn't purchase the track from iTunes, as long as you are subscribed to Spotify Premium, you'll get the latest tracks on your smartphone and play it any time, anywhere.