diff --git a/mopidy/__init__.py b/mopidy/__init__.py
index 13ce67c8..3d2498dd 100644
--- a/mopidy/__init__.py
+++ b/mopidy/__init__.py
@@ -12,7 +12,7 @@ def get_mpd_protocol_version():
 
 class MopidyException(Exception):
     def __init__(self, message):
-        self.message = message
+        self._message = message
 
     @property
     def message(self):
diff --git a/mopidy/backends/despotify/__init__.py b/mopidy/backends/despotify/__init__.py
index 713e0246..78c7f774 100644
--- a/mopidy/backends/despotify/__init__.py
+++ b/mopidy/backends/despotify/__init__.py
@@ -60,6 +60,9 @@ class DespotifyLibraryController(BaseLibraryController):
         track = self.backend.spotify.lookup(uri.encode(ENCODING))
         return DespotifyTranslator.to_mopidy_track(track)
 
+    def refresh(self, uri=None):
+        pass # TODO
+
     def search(self, **query):
         spotify_query = []
         for (field, values) in query.iteritems():
@@ -106,6 +109,9 @@ class DespotifyPlaybackController(BasePlaybackController):
             logger.error(e)
             return False
 
+    def _seek(self, time_position):
+        pass # TODO
+
     def _stop(self):
         try:
             self.backend.spotify.stop()
@@ -116,6 +122,15 @@ class DespotifyPlaybackController(BasePlaybackController):
 
 
 class DespotifyStoredPlaylistsController(BaseStoredPlaylistsController):
+    def create(self, name):
+        pass # TODO
+
+    def delete(self, playlist):
+        pass # TODO
+
+    def lookup(self, uri):
+        pass # TODO
+
     def refresh(self):
         logger.info(u'Caching stored playlists')
         playlists = []
@@ -127,6 +142,12 @@ class DespotifyStoredPlaylistsController(BaseStoredPlaylistsController):
             u', '.join([u'<%s>' % p.name for p in self.playlists]))
         logger.info(u'Done caching stored playlists')
 
+    def rename(self, playlist, new_name):
+        pass # TODO
+
+    def save(self, playlist):
+        pass # TODO
+
 
 class DespotifyTranslator(object):
     @classmethod
diff --git a/mopidy/backends/dummy/__init__.py b/mopidy/backends/dummy/__init__.py
index 2fd376a2..98257f18 100644
--- a/mopidy/backends/dummy/__init__.py
+++ b/mopidy/backends/dummy/__init__.py
@@ -19,21 +19,28 @@ class DummyBackend(BaseBackend):
         self.stored_playlists = DummyStoredPlaylistsController(backend=self)
         self.uri_handlers = [u'dummy:']
 
+
 class DummyCurrentPlaylistController(BaseCurrentPlaylistController):
     pass
 
+
 class DummyLibraryController(BaseLibraryController):
     _library = []
 
+    def find_exact(self, **query):
+        return Playlist()
+
     def lookup(self, uri):
         matches = filter(lambda t: uri == t.uri, self._library)
         if matches:
             return matches[0]
 
+    def refresh(self, uri=None):
+        pass
+
     def search(self, **query):
         return Playlist()
 
-    find_exact = search
 
 class DummyPlaybackController(BasePlaybackController):
     def _next(self, track):
@@ -51,6 +58,33 @@ class DummyPlaybackController(BasePlaybackController):
     def _resume(self):
         return True
 
+    def _seek(self, time_position):
+        pass
+
+    def _stop(self):
+        return True
+
+
 class DummyStoredPlaylistsController(BaseStoredPlaylistsController):
-    def search(self, query):
-        return [Playlist(name=query)]
+    _playlists = []
+
+    def create(self, name):
+        playlist = Playlist(name=name)
+        self._playlists.append(playlist)
+        return playlist
+
+    def delete(self, playlist):
+        self._playlists.remove(playlist)
+
+    def lookup(self, uri):
+        return filter(lambda p: p.uri == uri, self._playlists)
+
+    def refresh(self):
+        pass
+
+    def rename(self, playlist, new_name):
+        self._playlists[self._playlists.index(playlist)] = \
+            playlist.with_(name=new_name)
+
+    def save(self, playlist):
+        self._playlists.append(playlist)
diff --git a/mopidy/backends/gstreamer/__init__.py b/mopidy/backends/gstreamer/__init__.py
index 66d7f12b..74dd8332 100644
--- a/mopidy/backends/gstreamer/__init__.py
+++ b/mopidy/backends/gstreamer/__init__.py
@@ -1,7 +1,8 @@
 import gobject
 gobject.threads_init()
 # FIXME make sure we don't get hit by
-# http://jameswestby.net/weblog/tech/14-caution-python-multiprocessing-and-glib-dont-mix.html
+# http://jameswestby.net/
+#   weblog/tech/14-caution-python-multiprocessing-and-glib-dont-mix.html
 
 import pygst
 pygst.require('0.10')
@@ -71,9 +72,7 @@ class GStreamerPlaybackController(BasePlaybackController):
 
     def _set_state(self, state):
         self._bin.set_state(state)
-
-        result, new, old = self._bin.get_state()
-
+        (_, new, _) = self._bin.get_state()
         return new == state
 
     def _message(self, bus, message):
@@ -131,6 +130,9 @@ class GStreamerStoredPlaylistsController(BaseStoredPlaylistsController):
         self._folder = os.path.expanduser(settings.LOCAL_PLAYLIST_FOLDER)
         self.refresh()
 
+    def lookup(self, uri):
+        pass # TODO
+
     def refresh(self):
         playlists = []
 
@@ -285,7 +287,7 @@ class GStreamerLibraryController(BaseLibraryController):
         return Playlist(tracks=result_tracks)
 
     def _validate_query(self, query):
-        for (field, values) in query.iteritems():
+        for (_, values) in query.iteritems():
             if not values:
                 raise LookupError('Missing query')
             for value in values:
diff --git a/mopidy/frontends/mpd/frontend.py b/mopidy/frontends/mpd/frontend.py
index 08e6237e..46fb5ba5 100644
--- a/mopidy/frontends/mpd/frontend.py
+++ b/mopidy/frontends/mpd/frontend.py
@@ -321,7 +321,7 @@ class MpdFrontend(object):
         cp_tracks = self.backend.current_playlist.cp_tracks[start:end]
         if not cp_tracks:
             raise MpdArgError(u'Bad song index', command=u'delete')
-        for (cpid, track) in cp_tracks:
+        for (cpid, _) in cp_tracks:
             self.backend.current_playlist.remove(cpid=cpid)
 
     @handle_pattern(r'^delete "(?P<songpos>\d+)"$')
@@ -329,7 +329,7 @@ class MpdFrontend(object):
         """See :meth:`_current_playlist_delete_range`"""
         try:
             songpos = int(songpos)
-            (cpid, track) = self.backend.current_playlist.cp_tracks[songpos]
+            (cpid, _) = self.backend.current_playlist.cp_tracks[songpos]
             self.backend.current_playlist.remove(cpid=cpid)
         except IndexError:
             raise MpdArgError(u'Bad song index', command=u'delete')
@@ -552,7 +552,7 @@ class MpdFrontend(object):
         # XXX Naive implementation that returns all tracks as changed
         if int(version) != self.backend.current_playlist.version:
             result = []
-            for (position, (cpid, track)) in enumerate(
+            for (position, (cpid, _)) in enumerate(
                     self.backend.current_playlist.cp_tracks):
                 result.append((u'cpos', position))
                 result.append((u'Id', cpid))
@@ -630,7 +630,8 @@ class MpdFrontend(object):
         return [('songs', 0), ('playtime', 0)] # TODO
 
     @handle_pattern(r'^find '
-         r'(?P<mpd_query>("?([Aa]lbum|[Aa]rtist|[Ff]ilename|[Tt]itle|[Aa]ny)"? "[^"]+"\s?)+)$')
+         r'(?P<mpd_query>("?([Aa]lbum|[Aa]rtist|[Ff]ilename|[Tt]itle|[Aa]ny)"?'
+         ' "[^"]+"\s?)+)$')
     def _music_db_find(self, mpd_query):
         """
         *musicpd.org, music database section:*
@@ -655,7 +656,8 @@ class MpdFrontend(object):
         return self.backend.library.find_exact(**query).mpd_format()
 
     @handle_pattern(r'^findadd '
-         r'(?P<query>("?([Aa]lbum|[Aa]rtist|[Ff]ilename|[Tt]itle|[Aa]ny)"? "[^"]+"\s?)+)$')
+         r'(?P<query>("?([Aa]lbum|[Aa]rtist|[Ff]ilename|[Tt]itle|[Aa]ny)"? '
+         '"[^"]+"\s?)+)$')
     def _music_db_findadd(self, query):
         """
         *musicpd.org, music database section:*
@@ -666,14 +668,15 @@ class MpdFrontend(object):
             current playlist. ``TYPE`` can be any tag supported by MPD.
             ``WHAT`` is what to find.
         """
-        result = self._music_db_find(query)
         # TODO Add result to current playlist
-        #return result
+        #result = self._music_db_find(query)
 
     @handle_pattern(r'^list (?P<field>[Aa]rtist)$')
     @handle_pattern(r'^list "(?P<field>[Aa]rtist)"$')
-    @handle_pattern(r'^list (?P<field>album( artist)?)( "(?P<artist>[^"]+)")*$')
-    @handle_pattern(r'^list "(?P<field>album(" "artist)?)"( "(?P<artist>[^"]+)")*$')
+    @handle_pattern(r'^list (?P<field>album( artist)?)'
+        '( "(?P<artist>[^"]+)")*$')
+    @handle_pattern(r'^list "(?P<field>album(" "artist)?)"'
+        '( "(?P<artist>[^"]+)")*$')
     def _music_db_list(self, field, artist=None):
         """
         *musicpd.org, music database section:*
@@ -793,7 +796,8 @@ class MpdFrontend(object):
         return self._music_db_update(uri, rescan_unmodified_files=True)
 
     @handle_pattern(r'^search '
-         r'(?P<mpd_query>("?([Aa]lbum|[Aa]rtist|[Ff]ilename|[Tt]itle|[Aa]ny)"? "[^"]+"\s?)+)$')
+         r'(?P<mpd_query>("?([Aa]lbum|[Aa]rtist|[Ff]ilename|[Tt]itle|[Aa]ny)"?'
+         ' "[^"]+"\s?)+)$')
     def _music_db_search(self, mpd_query):
         """
         *musicpd.org, music database section:*
diff --git a/mopidy/frontends/mpd/serializer.py b/mopidy/frontends/mpd/serializer.py
index b8b6550b..07a58dd3 100644
--- a/mopidy/frontends/mpd/serializer.py
+++ b/mopidy/frontends/mpd/serializer.py
@@ -58,7 +58,7 @@ def tracks_to_mpd_format(tracks, start=0, end=None, cpids=None):
         end = len(tracks)
     tracks = tracks[start:end]
     positions = range(start, end)
-    cpids = cpids and cpids[start:end] or [None for t in tracks]
+    cpids = cpids and cpids[start:end] or [None for _ in tracks]
     assert len(tracks) == len(positions) == len(cpids)
     result = []
     for track, position, cpid in zip(tracks, positions, cpids):
diff --git a/mopidy/mixers/alsa.py b/mopidy/mixers/alsa.py
index bbb99772..efcb1e98 100644
--- a/mopidy/mixers/alsa.py
+++ b/mopidy/mixers/alsa.py
@@ -26,7 +26,8 @@ class AlsaMixer(BaseMixer):
                 return control
             else:
                 logger.debug(u'Mixer control not found, skipping: %s', control)
-        logger.warning(u'No working mixer controls found. Tried: %s', candidates)
+        logger.warning(u'No working mixer controls found. Tried: %s',
+            candidates)
 
     def _get_mixer_control_candidates(self):
         """