Fighting Threading?

I am new to C # and I am struggling with Threading (maybe).

When I start debugging and do one at a time, ... and the upload form fills in, the procedure is put in a weird position like this:

    static void Main(string[] args)
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        if (args.Length > 0)
            Application.Run(new frmMain(args[1]));
        else
            Application.Run(new frmMain());
    } // Stops here

      

        
        
        
      

    

I suspected this was ok, so I created a new project and executed it. and the result was different than before:

        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1()); // Stops here
        }

      

        
        
        
      

    

Now I am very confused so I need help. someone told me it is thread-safe, but I have not used threads in my code.

• PS

  ... I used NAudio library to play music, so I declared in frmMain class like this:

    using System;
    using System.Drawing;
    using System.IO;
    using System.Windows.Forms;
  
    using NAudio;
    using NAudio.Wave;
    using TagLib;
    (...)
    AudioFileReader _audioFileReader;
    IWavePlayer _waveOutDevice = new WaveOut();
    (...)
  
        
  
          
          
          
        
  
      

• PS

  ... 2 .. And this is the frmMain constructor.

      InitializeComponent();
  
      this.listMusic.DragOver += new DragEventHandler(this.FileDragOver);
      this.listMusic.DragDrop += new DragEventHandler(this.FileDragDrop);
      this.listMusic.DoubleClick += new EventHandler(this.listDoubleClick);
  
      _waveOutDevice.PlaybackStopped += new EventHandler<StoppedEventArgs>(this.PlaybackStopped);