logic to randomize between sound (or other things) with weighted priorities

WeightedPlayback

bool WeightedPlaylist()
{
  bool playlistResult = false;
	int playListLength = _playlist.Clips.Count;
  int totalWeight = 0;
	for (int i = 0; i < _playlist.Clips.Count; i++) {
		totalWeight += _playlist.Weights[i];
	}
	
	int choice = 0;
	while (true) {
		choice = Random.Range (0, totalWeight);
		_state._currentIndex = GetWeightedClip (choice, totalWeight);
		playlistResult = LastPlayedCheck (playListLength);
		if (playlistResult == true) {
			break;
		}
	}
	_state._nextSound = _playlist.Clips[_state._currentIndex];
	//Debug.Log (_sound + "'s current index swithced to: " + _state._currentIndex);
	return playlistResult;
}
	
int GetWeightedClip (int weight, int totalWeight)
{
	int returnIndex = 0;

	int threshhold = 0;
	for (int i = 0; i < _playlist.Weights.Count; i++) {
		threshhold += _playlist.Weights [i];
		if (weight < threshhold) {
			returnIndex = i;
		}
	}

	return returnIndex;
}

bool LastPlayedCheck(int playListLength)
{
	bool playlistResult = false;
	if (playListLength > 1) { // if no repeat is even possible
		if (_state._currentIndex != _state._lastPlayed || !_properties._playbackProps.DontRepeatLast) { // checking for repeats, this is where multiple previous played clips would be checked
			playlistResult = true;
		} else {
			playlistResult = false;
		}
	} else
	{
		playlistResult = true;
	}
	return playlistResult;
}

Requires a List() to hold sounds and a List() to hold weights