diff --git a/beet b/beet
index a398c6939..c5699a5ac 100755
--- a/beet
+++ b/beet
@@ -10,7 +10,7 @@
 # distribute, sublicense, and/or sell copies of the Software, and to
 # permit persons to whom the Software is furnished to do so, subject to
 # the following conditions:
-# 
+#
 # The above copyright notice and this permission notice shall be
 # included in all copies or substantial portions of the Software.
 
@@ -18,4 +18,3 @@ import beets.ui
 
 if __name__ == '__main__':
     beets.ui.main()
-
diff --git a/beets/dbcore/query.py b/beets/dbcore/query.py
index 4c888302d..805f2cac9 100644
--- a/beets/dbcore/query.py
+++ b/beets/dbcore/query.py
@@ -104,8 +104,11 @@ class StringFieldQuery(FieldQuery):
 class SubstringQuery(StringFieldQuery):
     """A query that matches a substring in a specific item field."""
     def col_clause(self):
-        search = '%' + (self.pattern.replace('\\','\\\\').replace('%','\\%')
-                            .replace('_','\\_')) + '%'
+        pattern = (self.pattern
+                       .replace('\\', '\\\\')
+                       .replace('%', '\\%')
+                       .replace('_', '\\_'))
+        search = '%' + pattern + '%'
         clause = self.field + " like ? escape '\\'"
         subvals = [search]
         return clause, subvals
@@ -236,12 +239,16 @@ class CollectionQuery(Query):
         self.subqueries = subqueries
 
     # Act like a sequence.
+
     def __len__(self):
         return len(self.subqueries)
+
     def __getitem__(self, key):
         return self.subqueries[key]
+
     def __iter__(self):
         return iter(self.subqueries)
+
     def __contains__(self, item):
         return item in self.subqueries
 
@@ -334,10 +341,8 @@ class FalseQuery(Query):
         return False
 
 
-
 # Time/date queries.
 
-
 def _to_epoch_time(date):
     """Convert a `datetime` object to an integer number of seconds since
     the (local) Unix epoch.
diff --git a/beets/dbcore/types.py b/beets/dbcore/types.py
index ccd260c0d..573775467 100644
--- a/beets/dbcore/types.py
+++ b/beets/dbcore/types.py
@@ -18,10 +18,8 @@ from . import query
 from beets.util import str2bool
 
 
-
 # Abstract base.
 
-
 class Type(object):
     """An object encapsulating the type of a model field. Includes
     information about how to store, query, format, and parse a given
@@ -63,10 +61,8 @@ class Type(object):
             return value
 
 
-
 # Reusable types.
 
-
 class Integer(Type):
     """A basic integer type.
     """
diff --git a/beets/mediafile.py b/beets/mediafile.py
index 7e76be2ff..29cb4f396 100644
--- a/beets/mediafile.py
+++ b/beets/mediafile.py
@@ -53,34 +53,8 @@ import enum
 
 __all__ = ['UnreadableFileError', 'FileTypeError', 'MediaFile']
 
-
-
-# Logger.
 log = logging.getLogger('beets')
 
-
-
-# Exceptions.
-
-class UnreadableFileError(Exception):
-    """Indicates a file that MediaFile can't read.
-    """
-    pass
-
-class FileTypeError(UnreadableFileError):
-    """Raised for files that don't seem to have a type MediaFile
-    supports.
-    """
-    pass
-
-class MutagenError(UnreadableFileError):
-    """Raised when Mutagen fails unexpectedly---probably due to a bug.
-    """
-
-
-
-# Constants.
-
 # Human-readable type names.
 TYPES = {
     'mp3':  'MP3',
@@ -96,6 +70,25 @@ TYPES = {
 }
 
 
+# Exceptions.
+
+class UnreadableFileError(Exception):
+    """Indicates a file that MediaFile can't read.
+    """
+    pass
+
+
+class FileTypeError(UnreadableFileError):
+    """Raised for files that don't seem to have a type MediaFile
+    supports.
+    """
+    pass
+
+
+class MutagenError(UnreadableFileError):
+    """Raised when Mutagen fails unexpectedly---probably due to a bug.
+    """
+
 
 # Utility.
 
@@ -161,7 +154,6 @@ def _safe_cast(out_type, val):
         return val
 
 
-
 # Image coding for ASF/WMA.
 
 def _unpack_asf_image(data):
@@ -189,6 +181,7 @@ def _unpack_asf_image(data):
     return (mime.decode("utf-16-le"), image_data, type,
             description.decode("utf-16-le"))
 
+
 def _pack_asf_image(mime, data, type=3, description=""):
     """Pack image data for a WM/Picture tag.
     """
@@ -199,7 +192,6 @@ def _pack_asf_image(mime, data, type=3, description=""):
     return tag_data
 
 
-
 # iTunes Sound Check encoding.
 
 def _sc_decode(soundcheck):
@@ -237,6 +229,7 @@ def _sc_decode(soundcheck):
 
     return round(gain, 2), round(peak, 6)
 
+
 def _sc_encode(gain, peak):
     """Encode ReplayGain gain/peak values as a Sound Check string.
     """
@@ -261,10 +254,8 @@ def _sc_encode(gain, peak):
     return (u' %08X' * 10) % values
 
 
-
 # Cover art and other images.
 
-
 def _image_mime_type(data):
     """Return the MIME type of the image data (a bytestring).
     """
@@ -341,7 +332,6 @@ class Image(object):
         return self.type.value
 
 
-
 # StorageStyle classes describe strategies for accessing values in
 # Mutagen file objects.
 
@@ -417,7 +407,7 @@ class StorageStyle(object):
         return the represented value.
         """
         if self.suffix and isinstance(mutagen_value, unicode) \
-                       and mutagen_value.endswith(self.suffix):
+           and mutagen_value.endswith(self.suffix):
             return mutagen_value[:-len(self.suffix)]
         else:
             return mutagen_value
@@ -588,10 +578,11 @@ class MP4ListStorageStyle(ListStorageStyle, MP4StorageStyle):
 
 
 class MP4SoundCheckStorageStyle(SoundCheckStorageStyleMixin, MP4StorageStyle):
-    def __init__(self, index=0, **kwargs):
-        super(MP4SoundCheckStorageStyle, self).__init__(**kwargs)
+    def __init__(self, key, index=0, **kwargs):
+        super(MP4SoundCheckStorageStyle, self).__init__(key, **kwargs)
         self.index = index
 
+
 class MP4BoolStorageStyle(MP4StorageStyle):
     """A style for booleans in MPEG-4 files. (MPEG-4 has an atom type
     specifically for representing booleans.)
@@ -716,7 +707,10 @@ class MP3DescStorageStyle(MP3StorageStyle):
         # need to make a new frame?
         if not found:
             frame = mutagen.id3.Frames[self.key](
-                    desc=str(self.description), text=value, encoding=3)
+                desc=str(self.description),
+                text=value,
+                encoding=3
+            )
             if self.id3_lang:
                 frame.lang = self.id3_lang
             mutagen_file.tags.add(frame)
@@ -832,7 +826,8 @@ class VorbisImageStorageStyle(ListStorageStyle):
 
     def __init__(self):
         super(VorbisImageStorageStyle, self).__init__(
-                key='metadata_block_picture')
+            key='metadata_block_picture'
+        )
         self.as_type = str
 
     def fetch(self, mutagen_file):
@@ -849,7 +844,7 @@ class VorbisImageStorageStyle(ListStorageStyle):
             except (TypeError, AttributeError):
                 continue
             images.append(Image(data=pic.data, desc=pic.desc,
-                                   type=pic.type))
+                                type=pic.type))
         return images
 
     def store(self, mutagen_file, image_data):
@@ -904,7 +899,6 @@ class FlacImageStorageStyle(ListStorageStyle):
         return pic
 
 
-
 # MediaField is a descriptor that represents a single logical field. It
 # aggregates several StorageStyles describing how to access the data for
 # each file type.
@@ -1141,10 +1135,8 @@ class ImageListField(MediaField):
             style.set_list(mediafile.mgfile, images)
 
 
-
 # MediaFile is a collection of fields.
 
-
 class MediaFile(object):
     """Represents a multimedia file on disk and provides access to its
     metadata.
@@ -1186,10 +1178,11 @@ class MediaFile(object):
             log.error('uncaught Mutagen exception in open: {0}'.format(exc))
             raise MutagenError('Mutagen raised an exception')
 
-        if self.mgfile is None: # Mutagen couldn't guess the type
+        if self.mgfile is None:
+            # Mutagen couldn't guess the type
             raise FileTypeError('file type unsupported by Mutagen')
-        elif type(self.mgfile).__name__ == 'M4A' or \
-             type(self.mgfile).__name__ == 'MP4':
+        elif (type(self.mgfile).__name__ == 'M4A' or
+              type(self.mgfile).__name__ == 'MP4'):
             # This hack differentiates AAC and ALAC until we find a more
             # deterministic approach. Mutagen only sets the sample rate
             # for AAC files. See:
@@ -1199,8 +1192,8 @@ class MediaFile(object):
                 self.type = 'aac'
             else:
                 self.type = 'alac'
-        elif type(self.mgfile).__name__ == 'ID3' or \
-             type(self.mgfile).__name__ == 'MP3':
+        elif (type(self.mgfile).__name__ == 'ID3' or
+              type(self.mgfile).__name__ == 'MP3'):
             self.type = 'mp3'
         elif type(self.mgfile).__name__ == 'FLAC':
             self.type = 'flac'
@@ -1261,7 +1254,6 @@ class MediaFile(object):
             for tag in self.mgfile.keys():
                 del self.mgfile[tag]
 
-
     # Convenient access to the set of available fields.
 
     @classmethod
@@ -1313,7 +1305,6 @@ class MediaFile(object):
             if field in dict:
                 setattr(self, field, dict[field])
 
-
     # Field definitions.
 
     title = MediaField(
@@ -1487,8 +1478,8 @@ class MediaFile(object):
     )
     country = MediaField(
         MP3DescStorageStyle('MusicBrainz Album Release Country'),
-        MP4StorageStyle("----:com.apple.iTunes:MusicBrainz Album "
-                         "Release Country"),
+        MP4StorageStyle("----:com.apple.iTunes:MusicBrainz "
+                        "Album Release Country"),
         StorageStyle('RELEASECOUNTRY'),
         ASFStorageStyle('MusicBrainz/Album Release Country'),
     )
@@ -1603,63 +1594,101 @@ class MediaFile(object):
 
     # ReplayGain fields.
     rg_track_gain = MediaField(
-        MP3DescStorageStyle(u'REPLAYGAIN_TRACK_GAIN',
-                     float_places=2, suffix=u' dB'),
-        MP3DescStorageStyle(u'replaygain_track_gain',
-                     float_places=2, suffix=u' dB'),
-        MP3SoundCheckStorageStyle(key='COMM', index=0, desc=u'iTunNORM',
-                     id3_lang='eng'),
-        MP4StorageStyle(key='----:com.apple.iTunes:replaygain_track_gain',
-                     float_places=2, suffix=b' dB'),
-        MP4SoundCheckStorageStyle(key='----:com.apple.iTunes:iTunNORM',
-                     index=0),
-        StorageStyle(u'REPLAYGAIN_TRACK_GAIN',
-                     float_places=2, suffix=u' dB'),
-        ASFStorageStyle(u'replaygain_track_gain',
-                     float_places=2, suffix=u' dB'),
+        MP3DescStorageStyle(
+            u'REPLAYGAIN_TRACK_GAIN',
+            float_places=2, suffix=u' dB'
+        ),
+        MP3DescStorageStyle(
+            u'replaygain_track_gain',
+            float_places=2, suffix=u' dB'
+        ),
+        MP3SoundCheckStorageStyle(
+            key='COMM',
+            index=0, desc=u'iTunNORM',
+            id3_lang='eng'
+        ),
+        MP4StorageStyle(
+            '----:com.apple.iTunes:replaygain_track_gain',
+            float_places=2, suffix=b' dB'
+        ),
+        MP4SoundCheckStorageStyle(
+            '----:com.apple.iTunes:iTunNORM',
+            index=0
+        ),
+        StorageStyle(
+            u'REPLAYGAIN_TRACK_GAIN',
+            float_places=2, suffix=u' dB'
+        ),
+        ASFStorageStyle(
+            u'replaygain_track_gain',
+            float_places=2, suffix=u' dB'
+        ),
         out_type=float
     )
     rg_album_gain = MediaField(
-        MP3DescStorageStyle(u'REPLAYGAIN_ALBUM_GAIN',
-                     float_places=2, suffix=u' dB'),
-        MP3DescStorageStyle(u'replaygain_album_gain',
-                     float_places=2, suffix=u' dB'),
-        MP4SoundCheckStorageStyle(key='----:com.apple.iTunes:iTunNORM',
-                     index=1),
-        StorageStyle(u'REPLAYGAIN_ALBUM_GAIN',
-                     float_places=2, suffix=u' dB'),
-        ASFStorageStyle(u'replaygain_album_gain',
-                     float_places=2, suffix=u' dB'),
+        MP3DescStorageStyle(
+            u'REPLAYGAIN_ALBUM_GAIN',
+            float_places=2, suffix=u' dB'
+        ),
+        MP3DescStorageStyle(
+            u'replaygain_album_gain',
+            float_places=2, suffix=u' dB'
+        ),
+        MP4SoundCheckStorageStyle(
+            '----:com.apple.iTunes:iTunNORM',
+            index=1
+        ),
+        StorageStyle(
+            u'REPLAYGAIN_ALBUM_GAIN',
+            float_places=2, suffix=u' dB'
+        ),
+        ASFStorageStyle(
+            u'replaygain_album_gain',
+            float_places=2, suffix=u' dB'
+        ),
         out_type=float
     )
     rg_track_peak = MediaField(
-        MP3DescStorageStyle(u'REPLAYGAIN_TRACK_PEAK',
-                     float_places=6),
-        MP3DescStorageStyle(u'replaygain_track_peak',
-                     float_places=6),
-        MP3SoundCheckStorageStyle(key='COMM', index=1, desc=u'iTunNORM',
-                     id3_lang='eng'),
-        MP4StorageStyle('----:com.apple.iTunes:replaygain_track_peak',
-                     float_places=6),
-        MP4SoundCheckStorageStyle(key='----:com.apple.iTunes:iTunNORM',
-                     index=1),
-        StorageStyle(u'REPLAYGAIN_TRACK_PEAK',
-                     float_places=6),
-        ASFStorageStyle(u'replaygain_track_peak',
-                     float_places=6),
+        MP3DescStorageStyle(
+            u'REPLAYGAIN_TRACK_PEAK',
+            float_places=6
+        ),
+        MP3DescStorageStyle(
+            u'replaygain_track_peak',
+            float_places=6
+        ),
+        MP3SoundCheckStorageStyle(
+            key=u'COMM',
+            index=1, desc=u'iTunNORM',
+            id3_lang='eng'
+        ),
+        MP4StorageStyle(
+            '----:com.apple.iTunes:replaygain_track_peak',
+            float_places=6
+        ),
+        MP4SoundCheckStorageStyle(
+            '----:com.apple.iTunes:iTunNORM',
+            index=1
+        ),
+        StorageStyle(u'REPLAYGAIN_TRACK_PEAK', float_places=6),
+        ASFStorageStyle(u'replaygain_track_peak', float_places=6),
         out_type=float,
     )
     rg_album_peak = MediaField(
-        MP3DescStorageStyle(u'REPLAYGAIN_ALBUM_PEAK',
-                     float_places=6),
-        MP3DescStorageStyle(u'replaygain_album_peak',
-                     float_places=6),
-        MP4StorageStyle('----:com.apple.iTunes:replaygain_album_peak',
-                         float_places=6),
-        StorageStyle(u'REPLAYGAIN_ALBUM_PEAK',
-                         float_places=6),
-        ASFStorageStyle(u'replaygain_album_peak',
-                         float_places=6),
+        MP3DescStorageStyle(
+            u'REPLAYGAIN_ALBUM_PEAK',
+            float_places=6
+        ),
+        MP3DescStorageStyle(
+            u'replaygain_album_peak',
+            float_places=6
+        ),
+        MP4StorageStyle(
+            '----:com.apple.iTunes:replaygain_album_peak',
+            float_places=6
+        ),
+        StorageStyle(u'REPLAYGAIN_ALBUM_PEAK', float_places=6),
+        ASFStorageStyle(u'replaygain_album_peak', float_places=6),
         out_type=float,
     )
 
diff --git a/beets/util/__init__.py b/beets/util/__init__.py
index 4dd229c91..ebc3806d5 100644
--- a/beets/util/__init__.py
+++ b/beets/util/__init__.py
@@ -143,7 +143,8 @@ def ancestry(path):
             break
         last_path = path
 
-        if path: # don't yield ''
+        if path:
+            # don't yield ''
             out.insert(0, path)
     return out
 
@@ -477,6 +478,8 @@ CHAR_REPLACE = [
     (re.compile(ur'\.$'), u'_'),  # Trailing dots.
     (re.compile(ur'\s+$'), u''),  # Trailing whitespace.
 ]
+
+
 def sanitize_path(path, replacements=None):
     """Takes a path (as a Unicode string) and makes sure that it is
     legal. Returns a new path. Only works with fragments; won't work
diff --git a/beets/vfs.py b/beets/vfs.py
index 235f36048..e940e21fe 100644
--- a/beets/vfs.py
+++ b/beets/vfs.py
@@ -20,6 +20,7 @@ from beets import util
 
 Node = namedtuple('Node', ['files', 'dirs'])
 
+
 def _insert(node, path, itemid):
     """Insert an item into a virtual filesystem node."""
     if len(path) == 1:
@@ -33,6 +34,7 @@ def _insert(node, path, itemid):
             node.dirs[dirname] = Node({}, {})
         _insert(node.dirs[dirname], rest, itemid)
 
+
 def libtree(lib):
     """Generates a filesystem-like directory tree for the files
     contained in `lib`. Filesystem nodes are (files, dirs) named