diff --git a/tidal_dl_ng/config.py b/tidal_dl_ng/config.py
index 95d30d9..12fa061 100644
--- a/tidal_dl_ng/config.py
+++ b/tidal_dl_ng/config.py
@@ -14,9 +14,9 @@ from tidal_dl_ng.model.cfg import Token as ModelToken
 
 
 class BaseConfig:
-    data: ModelSettings | ModelToken = None
-    file_path: str = None
-    cls_model: object = None
+    data: ModelSettings | ModelToken
+    file_path: str
+    cls_model: ModelSettings | ModelToken
     path_base: str = path_base()
 
     def save(self, config_to_compare: str = None) -> None:
@@ -69,22 +69,19 @@ class BaseConfig:
 
 
 class Settings(BaseConfig, metaclass=SingletonMeta):
-    cls_model = ModelSettings
-    data = None
-
     def __init__(self):
+        self.cls_model = ModelSettings
         self.file_path = path_file_settings()
         self.read(self.file_path)
 
 
 class Tidal(BaseConfig, metaclass=SingletonMeta):
-    cls_model = ModelToken
-    session: tidalapi.Session = None
-    data: ModelToken = None
+    session: tidalapi.Session
     token_from_storage: bool = False
-    settings: Settings = None
+    settings: Settings
 
     def __init__(self, settings: Settings = None):
+        self.cls_model = ModelToken
         tidal_config: tidalapi.Config = tidalapi.Config(item_limit=10000)
         self.session = tidalapi.Session(tidal_config)
         # self.session.config.client_id = "km8T1xS355y7dd3H"
diff --git a/tidal_dl_ng/download.py b/tidal_dl_ng/download.py
index 863aa20..24720fb 100644
--- a/tidal_dl_ng/download.py
+++ b/tidal_dl_ng/download.py
@@ -50,12 +50,12 @@ class RequestsClient:
 
 
 class Download:
-    settings: Settings = None
-    session: Session = None
+    settings: Settings
+    session: Session
     skip_existing: SkipExisting = False
-    fn_logger: Callable = None
-    progress_gui: ProgressBars = None
-    progress: Progress = None
+    fn_logger: Callable
+    progress_gui: ProgressBars
+    progress: Progress
 
     def __init__(
         self,
diff --git a/tidal_dl_ng/gui.py b/tidal_dl_ng/gui.py
index b99a2c7..a12cd82 100644
--- a/tidal_dl_ng/gui.py
+++ b/tidal_dl_ng/gui.py
@@ -32,19 +32,19 @@ from tidal_dl_ng.worker import Worker
 
 # TODO: Make more use of Exceptions
 class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
-    settings: Settings = None
-    tidal: Tidal = None
-    dl: Download = None
-    threadpool: QtCore.QThreadPool = None
-    tray: QtWidgets.QSystemTrayIcon = None
-    spinner: QtWaitingSpinner = None
+    settings: Settings
+    tidal: Tidal
+    dl: Download
+    threadpool: QtCore.QThreadPool
+    tray: QtWidgets.QSystemTrayIcon
+    spinner: QtWaitingSpinner
     spinner_start: QtCore.Signal = QtCore.Signal(QtWidgets.QWidget)
     spinner_stop: QtCore.Signal = QtCore.Signal()
-    pb_item: QtWidgets.QProgressBar = None
+    pb_item: QtWidgets.QProgressBar
     s_item_advance: QtCore.Signal = QtCore.Signal(float)
     s_item_name: QtCore.Signal = QtCore.Signal(str)
     s_list_name: QtCore.Signal = QtCore.Signal(str)
-    pb_list: QtWidgets.QProgressBar = None
+    pb_list: QtWidgets.QProgressBar
     s_list_advance: QtCore.Signal = QtCore.Signal(float)
     s_pb_reset: QtCore.Signal = QtCore.Signal()
     s_populate_tree_lists: QtCore.Signal = QtCore.Signal(list)
diff --git a/tidal_dl_ng/metadata.py b/tidal_dl_ng/metadata.py
index 7f7edd4..ce9bfa1 100644
--- a/tidal_dl_ng/metadata.py
+++ b/tidal_dl_ng/metadata.py
@@ -7,23 +7,23 @@ from tidal_dl_ng.constants import REQUESTS_TIMEOUT_SEC
 
 
 class Metadata:
-    path_file: str = None
-    title: str = None
-    album: str = None
-    albumartist: str = None
-    artists: [str] = None
-    copy_right: str = None
-    tracknumber: int = None
-    discnumber: int = None
-    totaldisc: int = None
-    totaltrack: int = None
-    date: str = None
-    composer: [str] = None
-    isrc: str = None
-    lyrics: str = None
-    path_cover: str = None
-    url_cover: str = None
-    m: mutagen.mp4.MP4 | mutagen.mp4.MP4 | mutagen.flac.FLAC = None
+    path_file: str
+    title: str
+    album: str
+    albumartist: str
+    artists: [str]
+    copy_right: str
+    tracknumber: int
+    discnumber: int
+    totaldisc: int
+    totaltrack: int
+    date: str
+    composer: [str]
+    isrc: str
+    lyrics: str
+    path_cover: str
+    url_cover: str
+    m: mutagen.mp4.MP4 | mutagen.mp4.MP4 | mutagen.flac.FLAC
 
     def __init__(
         self,