public void queueSound(FilenameURL filenameURL) {
		if (!toStream) {
			errorMessage("Method 'queueSound' may only be used for "
					+ "streaming and MIDI sources.");
			return;
		}
		if (filenameURL == null) {
			errorMessage("File not specified in method 'queueSound'");
			return;
		}

		synchronized (soundSequenceLock) {
			if (soundSequenceQueue == null)
				soundSequenceQueue = new LinkedList<FilenameURL>();
			soundSequenceQueue.add(filenameURL);
		}
	}