System.IO.FileInfo file = new System.IO.FileInfo(fileName);
            if (file.Exists)
            {
                System.IO.FileStream fs = null;
                fs = System.IO.File.Open(fileName, System.IO.FileMode.Open);
                byte[] btFile = new byte[fs.Length];
                fs.Read(btFile, 0, Convert.ToInt32(fs.Length));
                fs.Close();

                System.Web.HttpContext.Current.Response.Clear();
                System.Web.HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment; filename=" + file.Name);
                System.Web.HttpContext.Current.Response.AddHeader("Content-Length", file.Length.ToString());
                System.Web.HttpContext.Current.Response.ContentType = "audio/mpeg3";
                System.Web.HttpContext.Current.Response.BinaryWrite(btFile);
            }