public class LastFmAutoComplete
{
    public string Artist { get; set; }
    public string Album { get; set; }
    public string Track { get; set; }
    public TimeSpan Duration { get; set; }
    public string Id { get; set; }
    public string Image { get; set; }
    public string Reach { get; set; }
    public string Resid { get; set; }
    public AutoCompleteType Restype { get; set; }
    public string Weight { get; set; }

    public static AutoCompleteType ParseAutoCompleteType(string input)
    {
        var inputInt = int.Parse(input);
        return (AutoCompleteType)inputInt;
    }

    public enum AutoCompleteType
    {
        Artist = 6,
        Album = 8,
        Group = 20,
        Tag = 32,
        Track = 9,
        Label = 10,
        Event = 29
    }
}

    public List<LastFmAutoComplete> RequestAutocomplete(string query)
    {
        var returnValue = new List<LastFmAutoComplete>();

        if (string.IsNullOrEmpty(query))
            return returnValue;

        using (var autoCompleteDownloader = new WebClient())
        {
            var jsonString = autoCompleteDownloader.DownloadString(string.Format("http://last.fm/search/autocomplete?q={0}&force=1", query));

            var jsonParser = new fastJSON.JsonParser(jsonString);

            var decodedJson = (Dictionary<string, object>)jsonParser.Decode();
            var responseBlock = (Dictionary<string, object>)decodedJson["response"];
            var docsBlock = (ArrayList)responseBlock["docs"];

            foreach (Dictionary<string, object> doc in docsBlock)
            {
                var tmpAutoCompleteData = new LastFmAutoComplete
                {
                    Restype = LastFmAutoComplete.ParseAutoCompleteType(doc["restype"].ToString())
                };


                if (tmpAutoCompleteData.Restype == LastFmAutoComplete.AutoCompleteType.Tag || tmpAutoCompleteData.Restype == LastFmAutoComplete.AutoCompleteType.Group || tmpAutoCompleteData.Restype == LastFmAutoComplete.AutoCompleteType.Label || tmpAutoCompleteData.Restype == LastFmAutoComplete.AutoCompleteType.Event)
                    break;

                tmpAutoCompleteData.Artist = doc["artist"].ToString();

                if (doc.ContainsKey("album"))
                    tmpAutoCompleteData.Album = doc["album"].ToString();

                if (doc.ContainsKey("track"))
                    tmpAutoCompleteData.Track = doc["track"].ToString();

                if (doc.ContainsKey("duration"))
                    tmpAutoCompleteData.Duration = TimeSpan.FromSeconds(int.Parse(doc["duration"].ToString()));

                tmpAutoCompleteData.Id = doc["id"].ToString();
                if (doc.ContainsKey("image"))
                    tmpAutoCompleteData.Image = string.Format("http://userserve-ak.last.fm/serve/64s/{0}", doc["image"]);
                tmpAutoCompleteData.Reach = doc["reach"].ToString();
                tmpAutoCompleteData.Resid = doc["resid"].ToString();
                tmpAutoCompleteData.Weight = doc["weight"].ToString();

                returnValue.Add(tmpAutoCompleteData);
            }

            return returnValue;
        }
    }