C# Empty Contents Of A MemoryStream

private void Operation()
{
    //Instalize The MemoryStream(This Is To Store All The Wave Data Into Memory
    MemoryStream stream = new MemoryStream();

    //Construct The Note Sound And Put It Into The Stream
    PlayNote(stream, 180, 5000, false, NoteToPlayFreq, 1, 5000);

    // Jump Back To The Beginning Of The Stream
    stream.Position = 0;

    //Instalize A New Instance Of The Soundplayer Class
    SoundPlayer player = new SoundPlayer(stream);
        
    //Play The Note
    player.PlaySync();

    //This Is Supposed To Clear The Stream But It Dosent
    stream.Dispose();

    //Raise the NoteCompletedEvent event at the end of the program loop
    NoteCompletedEvent();
        
}

public void PlayNote(Stream output, double tempo, short defaultVolume, bool closeUnderlyingStream, float frequency, double length, short volume)
{
    this._tempo = tempo;

    _writer = new WaveWriter16Bit(output, 44100, false, closeUnderlyingStream);

    _defaultVolume = defaultVolume;


    if (volume < 0)
        throw new ArgumentOutOfRangeException("volume", "Volume must be greater than or equal to zero.");

    double samplesPerCycle = _writer.SampleRate / frequency;

    int samplesForNote = (int)(_writer.SampleRate * length * 60 / Tempo);


    Sample16Bit sample = new Sample16Bit();

    for (int currentSample = 0; currentSample < samplesForNote; currentSample++)
    {
        bool endOfStream = true;

        if (_writer.CurrentSample < _writer.NumberOfSamples)
        {
            sample = _writer.Read();
            endOfStream = false;
        }
        else
            sample.LeftChannel = 0;

        // If we're at the end of the note, fade out linearly.
        // This causes two back-to-back notes with the same frequency
        // to have a break between them, rather than being one
        // continuous tone.
        int distanceFromEnd = samplesForNote - currentSample;
        short finalVolume = distanceFromEnd < 1000 ? ((short)(volume * distanceFromEnd / 1000)) : volume;

        double sampleValue = Math.Sin(currentSample / samplesPerCycle * 2 * Math.PI) * finalVolume + sample.LeftChannel;

        if (sampleValue > short.MaxValue)
            sampleValue = short.MaxValue;
        else if (sampleValue < short.MinValue)
            sampleValue = short.MinValue;

        sample.LeftChannel = (short)(sampleValue);

        if (endOfStream == false)
            _writer.CurrentSample--;

        _writer.Write(sample);
    }

    if (_writer != null)
        _writer.Close();
}