     private let trackListButton = UIButton(type: .custom)
     
     private var audioPlayer: AVPlayer!
+    private var audioFileName: String?
+    private var audioArtistName: String?
     
     private var musicType: MusicType = .library
     
     private let volumeSlider: UISlider = {
-        return MPVolumeView().subviews.filter { $0 is UISlider }.map { $0 as! UISlider }.first!
+        let slider = MPVolumeView().subviews.filter { $0 is UISlider }.map { $0 as! UISlider }.first!
+        slider.isUserInteractionEnabled = true
+        return slider
     }()
     
     private var verticalConstraints: [NSLayoutConstraint] = []

        icloudDocButton.setBackgroundImage(#imageLiteral(resourceName: "Cloud"), for: UIControlState())
        icloudDocButton.addTarget(self, action: #selector(ViewController.presentCloudDocPicker), for: .touchUpInside)
        
        songTitleLabel.font = .preferredFont(for: .title1)
        songTitleLabel.textAlignment = .center
        
        albumTitleLabel.font = .preferredFont(for: .body)

        
    }
    
    func updateAlbumImage(to image: UIImage?) {
        guard let image = image else {
            self.imageView.image = nil
            self.backgroundImageView.image = nil
            return
        }
        let isDarkColor = image.averageColor.isDarkColor
        let blurEffect = isDarkColor ? UIBlurEffect(style: .light) : UIBlurEffect(style: .dark)
        UIView.animate(withDuration: 0.5) {
