Connector.cs

using System.Configuration;
using System.IO;
using System.Net;

namespace rdi_server.service
{
    public class Connector
    {
        private string Host { get; }
        private WebRequest _request;
        public WebResponse Response;
        public string ConnectionStatus;
        private Stream _dataStream;
        private StreamReader _reader;

        public Connector(string config)
        {
            Host = ConfigurationManager.AppSettings[config];
           
        }

        public string GetData()
        {
            _request = WebRequest.Create(Host);
            _request.Credentials = CredentialCache.DefaultCredentials;
            Response = _request.GetResponse();
            ConnectionStatus = (((HttpWebResponse)Response).StatusDescription);
            _dataStream = Response.GetResponseStream();
            _reader = new StreamReader(_dataStream);
            var toReturn = _reader.ReadToEnd();
            _reader.Close();
            Response.Close();
            return toReturn;
        }
    }
}

DomainDAO.cs

using System;
using System.Data.SqlClient;
using rdi_musica.core;

namespace rdi_server.service
{
    public static class DomainDAO
    {
        public static int InsertUsuario(SqlConnection connection, Usuario usuario)
        {
            var qry =
                String.Format(
                    "IF (NOT EXISTS(SELECT * FROM Usuario WHERE Id = {0})) BEGIN INSERT INTO Usuario(Nome, Email, Senha, DtCadastro, Ativo) VALUES( '{1}', '{2}', '{3}', convert(datetime,'{4}',105), '{5}') END ELSE BEGIN UPDATE Usuario SET Nome = '{1}', Email = '{2}', Senha = '{3}', DtCadastro = convert(datetime,'{4}',105), Ativo = '{5}' WHERE Id = {0} END",
                    usuario.Id, usuario.Nome, usuario.Email, usuario.Senha, usuario.DtCadastro.ToString("g"), usuario.Ativo);
            var query = new SqlCommand(qry ,connection);

            return query.ExecuteNonQuery();
        }

        public static int InsertGenero(SqlConnection connection, Genero genero)
        {
            var qry =
                String.Format(
                    "IF (NOT EXISTS(SELECT * FROM Genero WHERE Id = {0})) BEGIN INSERT INTO Genero(Nome, Descricao, CriadorId, DtCriacao, Ativo) VALUES( '{1}', '{2}', '{3}', convert(datetime,'{4}',105), '{5}') END ELSE BEGIN UPDATE Genero SET Nome = '{1}', Descricao = '{2}', CriadorId = '{3}', DtCriacao = convert(datetime,'{4}',105), Ativo = '{5}' WHERE Id = {0} END",
                    genero.Id, genero.Nome, genero.Descricao, genero.CriadorId, genero.DtCriacao.ToString("g"), genero.Ativo);
            var query = new SqlCommand(qry, connection);

            return query.ExecuteNonQuery();
        }

        public static int InsertBanda(SqlConnection connection, Banda banda)
        {
            var qry =
                String.Format(
                    "IF (NOT EXISTS(SELECT * FROM Banda WHERE Id = {0})) BEGIN INSERT INTO Banda(Nome, Descricao, CriadorId, DtCriacao, Ativo) VALUES( '{1}', '{2}', '{3}', convert(datetime,'{4}',105), '{5}') END ELSE BEGIN UPDATE Banda SET Nome = '{1}', Descricao = '{2}', CriadorId = '{3}', DtCriacao = convert(datetime,'{4}',105), Ativo = '{5}' WHERE Id = {0} END",
                    banda.Id, banda.Nome, banda.Descricao, banda.CriadorId, banda.DtCriacao.ToString("g"), banda.Ativo);
            var query = new SqlCommand(qry, connection);

            return query.ExecuteNonQuery();
        }

        public static int InsertMusica(SqlConnection connection, Musica musica)
        {
            var qry =
                String.Format(
                    "IF (NOT EXISTS(SELECT * FROM Musica WHERE Id = {0})) BEGIN INSERT INTO Musica(Titulo, BandaId, Link, DtCriacao, GeneroId, CriadorId, Ativo) VALUES( '{1}', {2}, '{3}', convert(datetime,'{4}',105), {5} , {6}, '{7}') END ELSE BEGIN UPDATE Musica SET Titulo = '{1}', BandaId = {2}, Link = '{3}', DtCriacao = convert(datetime,'{4}',105), Ativo = '{7}', GeneroId = {5}, CriadorId = {6}  WHERE Id = {0} END",
                    musica.Id, musica.Titulo, musica.BandaId, musica.Link, musica.DtCriacao.ToString("g"), musica.GeneroId, musica.CriadorId, musica.Ativo);
            var query = new SqlCommand(qry, connection);

            return query.ExecuteNonQuery();
        }
    }
}

Loader.cs

using System.Collections.Generic;
using System.Linq;
using rdi_musica.core;

namespace rdi_server.service
{
    public class Loader
    {
        public static List<Usuario> LoadUsuarios(Connector usuarioConnector)
        {
            return (List<Usuario>)Newtonsoft.Json.JsonConvert.DeserializeObject(usuarioConnector.GetData(), typeof(List<Usuario>));
        }
        public static List<Banda> LoadBandas(Connector bandaConnector)
        {
            var bandasDtos = (List<BandaDto>)Newtonsoft.Json.JsonConvert.DeserializeObject(bandaConnector.GetData(), typeof(List<BandaDto>));
            return bandasDtos.Select(dto => dto.ConvertToBanda()).ToList();
        }
        public static List<Genero> LoadGeneros(Connector generoConnector)
        {
            var musicasDtos = (List<GeneroDto>)Newtonsoft.Json.JsonConvert.DeserializeObject(generoConnector.GetData(), typeof(List<GeneroDto>));
            return musicasDtos.Select(dto => dto.ConvertToGenero()).ToList();
        }
        public static List<Musica> LoadMusicas(Connector musicaConnector)
        {
            var musicasDtos = (List<MusicaDto>)Newtonsoft.Json.JsonConvert.DeserializeObject(musicaConnector.GetData(), typeof(List<MusicaDto>));
            return musicasDtos.Select(dto => dto.ConvertToMusica()).ToList();
        }
    }
}

Program.cs

using System.ServiceProcess;

namespace rdi_server.service
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        static void Main()
        {

#if(!DEBUG)

            ServiceBase[] ServicesToRun;
            ServicesToRun = new ServiceBase[] 
			{ 
				new Service1() 
			};
            ServiceBase.Run(ServicesToRun);

#else
            Service1 service = new Service1();
            service.StartDebug();
#endif
        }
    }
}

Service1.cs

using System;
using System.Configuration;
using System.ServiceProcess;
using System.Threading;

namespace rdi_server.service
{
    public partial class Service1 : ServiceBase
    {

        private Thread _thread;

        private Updater _updater = new Updater();

        private readonly int Interval = Convert.ToInt32(ConfigurationManager.AppSettings["timer"]);
        private readonly string Connection = ConfigurationManager.AppSettings["connection"];

        private readonly Connector _usuarioConnector;
        private readonly Connector _bandaConnector;
        private readonly Connector _generoConnector;
        private readonly Connector _musicaConnector;

        public Service1()
        {
            _usuarioConnector = new Connector("UsuarioBase");
            _bandaConnector = new Connector("BandaBase");
            _generoConnector = new Connector("GeneroBase");
            _musicaConnector = new Connector("MusicaBase");

            InitializeComponent();
        }

        protected override void OnStart(string[] args)
        {
            StartDebug();
        }

        public void StartDebug()
        {
            _thread = new Thread(OnTime);
            _thread.Name = "My Worker Thread";
            _thread.Start();
        }

        protected override void OnStop()
        {

        }

        protected void OnTime()
        {
            while (true)
            {
                EventLog.WriteEntry("Dentro do WHILE foi executado!");
                _updater.Do(Connection, _usuarioConnector, _generoConnector, _bandaConnector, _musicaConnector);
                EventLog.WriteEntry("Fim do while");
                Thread.Sleep(Interval);
            }
        }
    }
}

Updater.cs

using rdi_musica.core;
using System.Collections.Generic;
using System.Data.SqlClient;

namespace rdi_server.service
{
    class Updater
    {
        public void Do(string Connection,
                            Connector usuario,
                            Connector genero,
                            Connector banda,
                            Connector musica)
        {

            var usuarios = Loader.LoadUsuarios(usuario);
            var generos = Loader.LoadGeneros(genero);
            var bandas = Loader.LoadBandas(banda);
            var musicas = Loader.LoadMusicas(musica);


            using (var connection = new SqlConnection(Connection))
            {
                connection.Open();

                foreach (var _usuario in usuarios)
                {
                    DomainDAO.InsertUsuario(connection, _usuario);
                }
                foreach (var _genero in generos)
                {
                    DomainDAO.InsertGenero(connection, _genero);
                }
                foreach (var _banda in bandas)
                {
                    DomainDAO.InsertBanda(connection, _banda);
                }
                foreach (var _musica in musicas)
                {
                    DomainDAO.InsertMusica(connection, _musica);
                }
            }
        }
    }
}