diff --git a/app/classes.py b/app/classes.py
index b51575b..0db282d 100644
--- a/app/classes.py
+++ b/app/classes.py
@@ -218,6 +218,12 @@ class InsertTrack:
     note: str
 
 
+@dataclass
+class SelectedRows:
+    playlist_id: int
+    rows: list[int]
+
+
 @dataclass
 class TrackAndPlaylist:
     playlist_id: int
@@ -233,25 +239,58 @@ class MusicMusterSignals(QObject):
      - https://stackoverflow.com/questions/62654525/emit-a-signal-from-another-class-to-main-class
     """
 
+    # Used to en/disable escape as a shortcut key to "clear selection".
+    # We disable it when editing a field in the playlist because we use
+    # escape there to abandon an edit.
     enable_escape_signal = pyqtSignal(bool)
+
+    # Signals that the next-cued track has changed. Used to update
+    # playlist headers.
     next_track_changed_signal = pyqtSignal()
+
+    # Signals that the playlist_id passed should resize all rows.
     resize_rows_signal = pyqtSignal(int)
+
+    # Signal to open browser at songfacts or wikipedia page matching
+    # passed string.
     search_songfacts_signal = pyqtSignal(str)
     search_wikipedia_signal = pyqtSignal(str)
+
+    # Displays a warning dialog
     show_warning_signal = pyqtSignal(str, str)
-    signal_add_track_to_header = pyqtSignal(int)
+
+    # Signal to add a track to a header row
+    signal_add_track_to_header = pyqtSignal(TrackAndPlaylist)
+
+    # Signal to receving model that rows will be / have been inserter
     signal_begin_insert_rows = pyqtSignal(InsertRows)
     signal_end_insert_rows = pyqtSignal(int)
+
+    # TBD
     signal_insert_track = pyqtSignal(InsertTrack)
-    signal_playlist_selected_rows = pyqtSignal(int, list)
+
+    # Keep track of which rows are selected (between playlist and model)
+    signal_playlist_selected_rows = pyqtSignal(SelectedRows)
+
+    # Signal to model that selected row is to be next row
     signal_set_next_row = pyqtSignal(int)
+
     # signal_set_next_track takes a PlaylistRow as an argument. We can't
     # specify that here as it requires us to import PlaylistRow from
     # playlistrow.py, which itself imports MusicMusterSignals
+
+    # TBD
     signal_set_next_track = pyqtSignal(object)
+
+    # Emited when a track starts playing
     signal_track_started = pyqtSignal(TrackAndPlaylist)
+
+    # Used by model to signal spanning of cells to playlist for headers
     span_cells_signal = pyqtSignal(int, int, int, int, int)
+
+    # Dispay status message to user
     status_message_signal = pyqtSignal(str, int)
+
     track_ended_signal = pyqtSignal()
 
     def __post_init__(self):
diff --git a/app/musicmuster.py b/app/musicmuster.py
index 5af05c3..61bbed4 100755
--- a/app/musicmuster.py
+++ b/app/musicmuster.py
@@ -1789,6 +1789,7 @@ class Window(QMainWindow):
             self.track_sequence.move_current_to_previous()
 
         # Tell playlist previous track has finished
+        # TODO: it should just catch track_ended_signal
         self.current.base_model.previous_track_ended()
 
         # Reset clocks
diff --git a/app/playlistmodel.py b/app/playlistmodel.py
index f7d4a56..d9b3524 100644
--- a/app/playlistmodel.py
+++ b/app/playlistmodel.py
@@ -36,6 +36,7 @@ from classes import (
     InsertRows,
     InsertTrack,
     MusicMusterSignals,
+    SelectedRows,
     TrackAndPlaylist,
 )
 from config import Config
@@ -1230,16 +1231,16 @@ class PlaylistModel(QAbstractTableModel):
         return True
 
     # @log_call
-    def set_selected_rows(self, playlist_id: int, selected_row_numbers: list[int]) -> None:
+    def set_selected_rows(self, selected_rows: SelectedRows) -> None:
         """
         Handle signal_playlist_selected_rows to keep track of which rows
         are selected in the view
         """
 
-        if playlist_id != self.playlist_id:
+        if selected_rows.playlist_id != self.playlist_id:
             return
 
-        self.selected_rows = [self.playlist_rows[a] for a in selected_row_numbers]
+        self.selected_rows = [self.playlist_rows[a] for a in selected_rows.rows]
 
     # @log_call
     def set_next_row(self, playlist_id: int) -> None:
@@ -1247,9 +1248,7 @@ class PlaylistModel(QAbstractTableModel):
         Handle signal_set_next_row
         """
 
-        log.debug(f"{self}: set_next_row({playlist_id=})")
         if playlist_id != self.playlist_id:
-            # Not for us
             return
 
         if len(self.selected_rows) == 0:
diff --git a/app/playlists.py b/app/playlists.py
index 077acfd..0b5fe09 100644
--- a/app/playlists.py
+++ b/app/playlists.py
@@ -40,6 +40,7 @@ from classes import (
     Col,
     MusicMusterSignals,
     PlaylistStyle,
+    SelectedRows,
     TrackAndPlaylist,
     TrackInfo
 )
@@ -471,7 +472,9 @@ class PlaylistTab(QTableView):
         selected_row_numbers = self.get_selected_rows()
 
         # Signal selected rows to model
-        self.signals.signal_playlist_selected_rows.emit(self.playlist_id, selected_row_numbers)
+        self.signals.signal_playlist_selected_rows.emit(
+            SelectedRows(self.playlist_id, selected_row_numbers)
+        )
 
         # Put sum of selected tracks' duration in status bar
         # If no rows are selected, we have nothing to do
diff --git a/app/utilities.py b/app/utilities.py
index 5c8c72f..820cd3d 100755
--- a/app/utilities.py
+++ b/app/utilities.py
@@ -91,6 +91,6 @@ def update_bitrates() -> None:
     for track in ds.tracks_all():
         try:
             t = get_tags(track.path)
-            ds.track_update(t)
+            ds.track_update(track.track_id, t._asdict())
         except FileNotFoundError:
             continue