CDPlayer player = new CDPlayer(Volume, song, command);
player.SetCommand(command);
When you declare CDPlayer class you use constructor to initialize property see below method.
public CDPlayer (int Voice, int CurrentTrack, string Command)
{
this.Voice = VolumeStatus(Voice);
this.CurrentTrack = CurrentTrack;
this.Command = Command;
}
here, remove VolumeStatus use only "this.Voice=Voice" because in VolumeStatus method you use Console.WriteLine to print volume set.
player.SetCommand(command);
this method also do same thing to print volume set.
case "Voice":
this.Voice = Keyboard.ReadInt("Set the new volume level (from 0 to 9): ");
Console.WriteLine(VolumeStatus(Voice));
break;