diff --git a/app/src/main/java/com/cappielloantonio/play/database/AppDatabase.java b/app/src/main/java/com/cappielloantonio/play/database/AppDatabase.java
index 1ab3f2cb..c1ac67b5 100644
--- a/app/src/main/java/com/cappielloantonio/play/database/AppDatabase.java
+++ b/app/src/main/java/com/cappielloantonio/play/database/AppDatabase.java
@@ -29,7 +29,7 @@ import com.cappielloantonio.play.model.Song;
 import com.cappielloantonio.play.model.SongArtistCross;
 import com.cappielloantonio.play.model.SongGenreCross;
 
-@Database(entities = {Album.class, Artist.class, Genre.class, Playlist.class, Song.class, RecentSearch.class, SongGenreCross.class, Queue.class, AlbumArtistCross.class, SongArtistCross.class, PlaylistSongCross.class}, version = 12, exportSchema = false)
+@Database(entities = {Album.class, Artist.class, Genre.class, Playlist.class, Song.class, RecentSearch.class, SongGenreCross.class, Queue.class, AlbumArtistCross.class, SongArtistCross.class, PlaylistSongCross.class}, version = 13, exportSchema = false)
 public abstract class AppDatabase extends RoomDatabase {
     private static final String TAG = "AppDatabase";
     private final static String DB_NAME = "play_db";
@@ -38,7 +38,7 @@ public abstract class AppDatabase extends RoomDatabase {
     public static synchronized AppDatabase getInstance(Context context) {
 
         if (instance == null && context != null) {
-            instance = Room.databaseBuilder(context.getApplicationContext(), AppDatabase.class, DB_NAME)
+            instance = Room.databaseBuilder(context, AppDatabase.class, DB_NAME)
                     .fallbackToDestructiveMigration()
                     .build();
         }
diff --git a/app/src/main/java/com/cappielloantonio/play/database/dao/PlaylistSongCrossDao.java b/app/src/main/java/com/cappielloantonio/play/database/dao/PlaylistSongCrossDao.java
index 279462bf..364f0db1 100644
--- a/app/src/main/java/com/cappielloantonio/play/database/dao/PlaylistSongCrossDao.java
+++ b/app/src/main/java/com/cappielloantonio/play/database/dao/PlaylistSongCrossDao.java
@@ -17,9 +17,6 @@ public interface PlaylistSongCrossDao {
     @Query("SELECT * FROM playlist_song_cross")
     LiveData<List<PlaylistSongCross>> getAll();
 
-    @Query("SELECT EXISTS(SELECT * FROM playlist_song_cross WHERE id = :id)")
-    boolean exist(String id);
-
     @Insert(onConflict = OnConflictStrategy.REPLACE)
     void insert(PlaylistSongCross playlistSongCross);
 
diff --git a/app/src/main/java/com/cappielloantonio/play/model/PlaylistSongCross.java b/app/src/main/java/com/cappielloantonio/play/model/PlaylistSongCross.java
index 6eca3b19..797efae9 100644
--- a/app/src/main/java/com/cappielloantonio/play/model/PlaylistSongCross.java
+++ b/app/src/main/java/com/cappielloantonio/play/model/PlaylistSongCross.java
@@ -5,16 +5,13 @@ import androidx.room.ColumnInfo;
 import androidx.room.Entity;
 import androidx.room.PrimaryKey;
 
-@Entity(tableName = "playlist_song_cross")
+@Entity(tableName = "playlist_song_cross", primaryKeys = {"playlist_id","song_id"})
 public class PlaylistSongCross {
     @NonNull
-    @PrimaryKey(autoGenerate = true)
-    @ColumnInfo(name = "id")
-    private int id;
-
     @ColumnInfo(name = "playlist_id")
     private String playlistId;
 
+    @NonNull
     @ColumnInfo(name = "song_id")
     private String songId;
 
@@ -23,14 +20,6 @@ public class PlaylistSongCross {
         this.songId = songId;
     }
 
-    public int getId() {
-        return id;
-    }
-
-    public void setId(int id) {
-        this.id = id;
-    }
-
     public String getPlaylistId() {
         return playlistId;
     }
diff --git a/app/src/main/java/com/cappielloantonio/play/repository/AlbumArtistRepository.java b/app/src/main/java/com/cappielloantonio/play/repository/AlbumArtistRepository.java
index bc4b9270..9a5eaf51 100644
--- a/app/src/main/java/com/cappielloantonio/play/repository/AlbumArtistRepository.java
+++ b/app/src/main/java/com/cappielloantonio/play/repository/AlbumArtistRepository.java
@@ -20,11 +20,11 @@ public class AlbumArtistRepository {
 
     public void insertAll(List<AlbumArtistCross> crosses) {
         try {
-            final Thread delete = new Thread(new DeleteAllAlbumArtistCrossThreadSafe(albumArtistCrossDao));
+            final Thread deleteAll = new Thread(new DeleteAllAlbumArtistCrossThreadSafe(albumArtistCrossDao));
             final Thread insertAll = new Thread(new InsertAllThreadSafe(albumArtistCrossDao, crosses));
 
-            delete.start();
-            delete.join();
+            deleteAll.start();
+            deleteAll.join();
             insertAll.start();
             insertAll.join();
         } catch (InterruptedException e) {
diff --git a/app/src/main/java/com/cappielloantonio/play/repository/AlbumRepository.java b/app/src/main/java/com/cappielloantonio/play/repository/AlbumRepository.java
index a396bde5..59e30042 100644
--- a/app/src/main/java/com/cappielloantonio/play/repository/AlbumRepository.java
+++ b/app/src/main/java/com/cappielloantonio/play/repository/AlbumRepository.java
@@ -64,9 +64,17 @@ public class AlbumRepository {
     }
 
     public void insertAll(ArrayList<Album> albums) {
-        InsertAllThreadSafe insertAll = new InsertAllThreadSafe(albumDao, albums);
-        Thread thread = new Thread(insertAll);
-        thread.start();
+        try {
+            final Thread deleteAll = new Thread(new DeleteAllThreadSafe(albumDao));
+            final Thread insertAll = new Thread(new InsertAllThreadSafe(albumDao, albums));
+
+            deleteAll.start();
+            deleteAll.join();
+            insertAll.start();
+            insertAll.join();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
     }
 
     public void deleteAll() {
@@ -158,7 +166,6 @@ public class AlbumRepository {
 
         @Override
         public void run() {
-            albumDao.deleteAll();
             albumDao.insertAll(albums);
         }
     }
diff --git a/app/src/main/java/com/cappielloantonio/play/repository/ArtistRepository.java b/app/src/main/java/com/cappielloantonio/play/repository/ArtistRepository.java
index 63b59e5a..026c2544 100644
--- a/app/src/main/java/com/cappielloantonio/play/repository/ArtistRepository.java
+++ b/app/src/main/java/com/cappielloantonio/play/repository/ArtistRepository.java
@@ -56,9 +56,17 @@ public class ArtistRepository {
     }
 
     public void insertAll(ArrayList<Artist> artists) {
-        InsertAllThreadSafe insertAll = new InsertAllThreadSafe(artistDao, artists);
-        Thread thread = new Thread(insertAll);
-        thread.start();
+        try {
+            final Thread deleteAll = new Thread(new DeleteAllThreadSafe(artistDao));
+            final Thread insertAll = new Thread(new InsertAllThreadSafe(artistDao, artists));
+
+            deleteAll.start();
+            deleteAll.join();
+            insertAll.start();
+            insertAll.join();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
     }
 
     public void deleteAll() {
@@ -117,7 +125,6 @@ public class ArtistRepository {
 
         @Override
         public void run() {
-            artistDao.deleteAll();
             artistDao.insertAll(artists);
         }
     }
diff --git a/app/src/main/java/com/cappielloantonio/play/repository/PlaylistRepository.java b/app/src/main/java/com/cappielloantonio/play/repository/PlaylistRepository.java
index ce83d47d..fcd478a5 100644
--- a/app/src/main/java/com/cappielloantonio/play/repository/PlaylistRepository.java
+++ b/app/src/main/java/com/cappielloantonio/play/repository/PlaylistRepository.java
@@ -26,9 +26,17 @@ public class PlaylistRepository {
     }
 
     public void insertAll(ArrayList<Playlist> playlists) {
-        InsertAllThreadSafe insertAll = new InsertAllThreadSafe(playlistDao, playlists);
-        Thread thread = new Thread(insertAll);
-        thread.start();
+        try {
+            final Thread deleteAll = new Thread(new DeleteAllThreadSafe(playlistDao));
+            final Thread insertAll = new Thread(new InsertAllThreadSafe(playlistDao, playlists));
+
+            deleteAll.start();
+            deleteAll.join();
+            insertAll.start();
+            insertAll.join();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
     }
 
     public void deleteAll() {
@@ -65,7 +73,6 @@ public class PlaylistRepository {
 
         @Override
         public void run() {
-            playlistDao.deleteAll();
             playlistDao.insertAll(playlists);
         }
     }
diff --git a/app/src/main/java/com/cappielloantonio/play/repository/PlaylistSongRepository.java b/app/src/main/java/com/cappielloantonio/play/repository/PlaylistSongRepository.java
index a9c32f37..0b50b320 100644
--- a/app/src/main/java/com/cappielloantonio/play/repository/PlaylistSongRepository.java
+++ b/app/src/main/java/com/cappielloantonio/play/repository/PlaylistSongRepository.java
@@ -24,12 +24,6 @@ public class PlaylistSongRepository {
         thread.start();
     }
 
-    public void deleteAll() {
-        DeleteAllPlaylistSongCrossThreadSafe delete = new DeleteAllPlaylistSongCrossThreadSafe(playlistSongCrossDao);
-        Thread thread = new Thread(delete);
-        thread.start();
-    }
-
     private static class InsertAllThreadSafe implements Runnable {
         private PlaylistSongCrossDao playlistSongCrossDao;
         private List<PlaylistSongCross> crosses;
@@ -45,6 +39,12 @@ public class PlaylistSongRepository {
         }
     }
 
+    public void deleteAll() {
+        DeleteAllPlaylistSongCrossThreadSafe delete = new DeleteAllPlaylistSongCrossThreadSafe(playlistSongCrossDao);
+        Thread thread = new Thread(delete);
+        thread.start();
+    }
+
     private static class DeleteAllPlaylistSongCrossThreadSafe implements Runnable {
         private PlaylistSongCrossDao playlistSongCrossDao;
 
diff --git a/app/src/main/java/com/cappielloantonio/play/repository/SongArtistRepository.java b/app/src/main/java/com/cappielloantonio/play/repository/SongArtistRepository.java
index 231ceda9..3966daae 100644
--- a/app/src/main/java/com/cappielloantonio/play/repository/SongArtistRepository.java
+++ b/app/src/main/java/com/cappielloantonio/play/repository/SongArtistRepository.java
@@ -20,11 +20,11 @@ public class SongArtistRepository {
 
     public void insertAll(List<SongArtistCross> crosses) {
         try {
-            final Thread delete = new Thread(new DeleteAllSongArtistCrossThreadSafe(songArtistCrossDao));
+            final Thread deleteAll = new Thread(new DeleteAllSongArtistCrossThreadSafe(songArtistCrossDao));
             final Thread insertAll = new Thread(new InsertAllThreadSafe(songArtistCrossDao, crosses));
 
-            delete.start();
-            delete.join();
+            deleteAll.start();
+            deleteAll.join();
             insertAll.start();
             insertAll.join();
         } catch (InterruptedException e) {
diff --git a/app/src/main/java/com/cappielloantonio/play/repository/SongGenreRepository.java b/app/src/main/java/com/cappielloantonio/play/repository/SongGenreRepository.java
new file mode 100644
index 00000000..7383c599
--- /dev/null
+++ b/app/src/main/java/com/cappielloantonio/play/repository/SongGenreRepository.java
@@ -0,0 +1,70 @@
+package com.cappielloantonio.play.repository;
+
+import android.app.Application;
+
+import com.cappielloantonio.play.database.AppDatabase;
+import com.cappielloantonio.play.database.dao.SongArtistCrossDao;
+import com.cappielloantonio.play.database.dao.SongGenreCrossDao;
+import com.cappielloantonio.play.model.SongArtistCross;
+import com.cappielloantonio.play.model.SongGenreCross;
+
+import java.util.List;
+
+public class SongGenreRepository {
+    private static final String TAG = "AlbumArtistRepository";
+
+    private SongGenreCrossDao songGenreCrossDao;
+
+    public SongGenreRepository(Application application) {
+        AppDatabase database = AppDatabase.getInstance(application);
+        songGenreCrossDao = database.songGenreCrossDao();
+    }
+
+    public void insertAll(List<SongGenreCross> crosses) {
+        try {
+            final Thread delete = new Thread(new DeleteAllSongGenreCrossThreadSafe(songGenreCrossDao));
+            final Thread insertAll = new Thread(new InsertAllThreadSafe(songGenreCrossDao, crosses));
+
+            delete.start();
+            delete.join();
+            insertAll.start();
+            insertAll.join();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public void deleteAll() {
+        DeleteAllSongGenreCrossThreadSafe delete = new DeleteAllSongGenreCrossThreadSafe(songGenreCrossDao);
+        Thread thread = new Thread(delete);
+        thread.start();
+    }
+
+    private static class InsertAllThreadSafe implements Runnable {
+        private SongGenreCrossDao songGenreCrossDao;
+        private List<SongGenreCross> crosses;
+
+        public InsertAllThreadSafe(SongGenreCrossDao songGenreCrossDao, List<SongGenreCross> crosses) {
+            this.songGenreCrossDao = songGenreCrossDao;
+            this.crosses = crosses;
+        }
+
+        @Override
+        public void run() {
+            songGenreCrossDao.insertAll(crosses);
+        }
+    }
+
+    private static class DeleteAllSongGenreCrossThreadSafe implements Runnable {
+        private SongGenreCrossDao songGenreCrossDao;
+
+        public DeleteAllSongGenreCrossThreadSafe(SongGenreCrossDao songGenreCrossDao) {
+            this.songGenreCrossDao = songGenreCrossDao;
+        }
+
+        @Override
+        public void run() {
+            songGenreCrossDao.deleteAll();
+        }
+    }
+}
diff --git a/app/src/main/java/com/cappielloantonio/play/repository/SongRepository.java b/app/src/main/java/com/cappielloantonio/play/repository/SongRepository.java
index 51a7ced1..3462df29 100644
--- a/app/src/main/java/com/cappielloantonio/play/repository/SongRepository.java
+++ b/app/src/main/java/com/cappielloantonio/play/repository/SongRepository.java
@@ -215,6 +215,18 @@ public class SongRepository {
     }
 
     public void insertAll(ArrayList<Song> songs) {
+        try {
+            final Thread deleteAll = new Thread(new DeleteAllSongThreadSafe(songDao));
+            final Thread insertAll = new Thread(new InsertAllThreadSafe(songDao, songGenreCrossDao, songs));
+
+            deleteAll.start();
+            deleteAll.join();
+            insertAll.start();
+            insertAll.join();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+
         InsertAllThreadSafe insertAll = new InsertAllThreadSafe(songDao, songGenreCrossDao, songs);
         Thread thread = new Thread(insertAll);
         thread.start();
@@ -405,8 +417,6 @@ public class SongRepository {
 
         @Override
         public void run() {
-            songDao.deleteAll();
-            songGenreCrossDao.deleteAll();
             songDao.insertAll(songs);
         }
     }
diff --git a/app/src/main/java/com/cappielloantonio/play/ui/fragment/PlaylistPageFragment.java b/app/src/main/java/com/cappielloantonio/play/ui/fragment/PlaylistPageFragment.java
index 7837164c..ac9e4109 100644
--- a/app/src/main/java/com/cappielloantonio/play/ui/fragment/PlaylistPageFragment.java
+++ b/app/src/main/java/com/cappielloantonio/play/ui/fragment/PlaylistPageFragment.java
@@ -37,7 +37,6 @@ public class PlaylistPageFragment extends Fragment {
         super.onActivityCreated(savedInstanceState);
 
         initAppBar();
-        initMusicButton();
     }
 
     @Override
@@ -50,6 +49,7 @@ public class PlaylistPageFragment extends Fragment {
 
         init();
         initBackCover();
+        initMusicButton();
         initSongsView();
 
         return view;
diff --git a/app/src/main/java/com/cappielloantonio/play/ui/fragment/SyncFragment.java b/app/src/main/java/com/cappielloantonio/play/ui/fragment/SyncFragment.java
index c9729f4b..ae81c5f7 100644
--- a/app/src/main/java/com/cappielloantonio/play/ui/fragment/SyncFragment.java
+++ b/app/src/main/java/com/cappielloantonio/play/ui/fragment/SyncFragment.java
@@ -30,6 +30,7 @@ import com.cappielloantonio.play.repository.GenreRepository;
 import com.cappielloantonio.play.repository.PlaylistRepository;
 import com.cappielloantonio.play.repository.PlaylistSongRepository;
 import com.cappielloantonio.play.repository.SongArtistRepository;
+import com.cappielloantonio.play.repository.SongGenreRepository;
 import com.cappielloantonio.play.repository.SongRepository;
 import com.cappielloantonio.play.ui.activity.MainActivity;
 import com.cappielloantonio.play.util.DownloadUtil;
@@ -55,6 +56,7 @@ public class SyncFragment extends Fragment {
     private ArtistRepository artistRepository;
     private PlaylistRepository playlistRepository;
     private GenreRepository genreRepository;
+    private SongGenreRepository songGenreRepository;
     private SongArtistRepository songArtistRepository;
     private AlbumArtistRepository albumArtistRepository;
     private PlaylistSongRepository playlistSongRepository;
@@ -82,6 +84,7 @@ public class SyncFragment extends Fragment {
         artistRepository = new ArtistRepository(activity.getApplication());
         playlistRepository = new PlaylistRepository(activity.getApplication());
         genreRepository = new GenreRepository(activity.getApplication());
+        songGenreRepository = new SongGenreRepository(activity.getApplication());
         songArtistRepository = new SongArtistRepository(activity.getApplication());
         albumArtistRepository = new AlbumArtistRepository(activity.getApplication());
         playlistSongRepository = new PlaylistSongRepository(activity.getApplication());
@@ -244,6 +247,7 @@ public class SyncFragment extends Fragment {
             @Override
             public void onLoadMedia(List<?> media) {
                 syncViewModel.setPlaylistList((ArrayList<Playlist>) media);
+                playlistSongRepository.deleteAll();
                 playlistRepository.insertAll(syncViewModel.getPlaylistList());
                 loadSectorInfo(PLAYLISTS, "Found " + syncViewModel.getPlaylistList().size() + " elements", true);
             }
@@ -260,15 +264,11 @@ public class SyncFragment extends Fragment {
             @Override
             public void onLoadMedia(List<?> media) {
                 syncViewModel.setSongList((ArrayList<Song>) media);
-
-                songRepository.deleteAllSongGenreCross();
+                songGenreRepository.deleteAll();
                 songRepository.insertAll(syncViewModel.getSongList());
-
                 syncSongArtistCross(syncViewModel.getSongList());
                 syncDownloadedSong();
-
                 loadSectorInfo(SONGS, "Found " + syncViewModel.getSongList().size() + " elements", true);
-
                 PreferenceUtil.getInstance(requireContext()).setSongNumber(syncViewModel.getSongList().size());
             }
         });
@@ -284,7 +284,7 @@ public class SyncFragment extends Fragment {
 
                 @Override
                 public void onLoadMedia(List<?> media) {
-                    songRepository.insertSongPerGenre((ArrayList<SongGenreCross>) media);
+                    songGenreRepository.insertAll((ArrayList<SongGenreCross>) media);
                     loadSectorInfo(SONG_X_GENRE, "Genre processed: " + genre.getName(), true);
                 }
             }, genre.id);