diff --git a/beets/library.py b/beets/library.py
index 33aa314bf..15151e9fe 100644
--- a/beets/library.py
+++ b/beets/library.py
@@ -402,6 +402,14 @@ class Item(LibModel):
     `write`.
     """
 
+    _media_tag_fields = set(MediaFile.fields()).intersection(_fields.keys())
+    """Set of item fields that are backed by *writable* `MediaFile` tag
+    fields.
+
+    This excludes fields that represent audio data, such as `bitrate` or
+    `length`.
+    """
+
     _formatter = FormattedItemMapping
 
     _sorts = {'artist': SmartArtistSort}
diff --git a/beets/ui/__init__.py b/beets/ui/__init__.py
index 558030a25..687d4b320 100644
--- a/beets/ui/__init__.py
+++ b/beets/ui/__init__.py
@@ -107,7 +107,7 @@ def print_(*strings):
         if isinstance(strings[0], unicode):
             txt = u' '.join(strings)
         else:
-            txt = ' '.join(strings)
+            txt = b' '.join(strings)
     else:
         txt = u''
     if isinstance(txt, unicode):
diff --git a/beets/ui/commands.py b/beets/ui/commands.py
index f6c1312d2..7446fb0b5 100644
--- a/beets/ui/commands.py
+++ b/beets/ui/commands.py
@@ -1428,7 +1428,7 @@ def write_items(lib, query, pretend, force):
 
         # Check for and display changes.
         changed = ui.show_model_changes(item, clean_item,
-                                        library.Item._media_fields, force)
+                                        library.Item._media_tag_fields, force)
         if (changed or force) and not pretend:
             item.try_sync()
 
diff --git a/beetsplug/scrub.py b/beetsplug/scrub.py
index a832c9466..5c0d74e6e 100644
--- a/beetsplug/scrub.py
+++ b/beetsplug/scrub.py
@@ -26,21 +26,21 @@ from beets import config
 from beets import mediafile
 
 _MUTAGEN_FORMATS = {
-    'asf': 'ASF',
-    'apev2': 'APEv2File',
-    'flac': 'FLAC',
-    'id3': 'ID3FileType',
-    'mp3': 'MP3',
-    'mp4': 'MP4',
-    'oggflac': 'OggFLAC',
-    'oggspeex': 'OggSpeex',
-    'oggtheora': 'OggTheora',
-    'oggvorbis': 'OggVorbis',
-    'oggopus': 'OggOpus',
-    'trueaudio': 'TrueAudio',
-    'wavpack': 'WavPack',
-    'monkeysaudio': 'MonkeysAudio',
-    'optimfrog': 'OptimFROG',
+    b'asf': b'ASF',
+    b'apev2': b'APEv2File',
+    b'flac': b'FLAC',
+    b'id3': b'ID3FileType',
+    b'mp3': b'MP3',
+    b'mp4': b'MP4',
+    b'oggflac': b'OggFLAC',
+    b'oggspeex': b'OggSpeex',
+    b'oggtheora': b'OggTheora',
+    b'oggvorbis': b'OggVorbis',
+    b'oggopus': b'OggOpus',
+    b'trueaudio': b'TrueAudio',
+    b'wavpack': b'WavPack',
+    b'monkeysaudio': b'MonkeysAudio',
+    b'optimfrog': b'OptimFROG',
 }
 
 
@@ -103,7 +103,7 @@ class ScrubPlugin(BeetsPlugin):
         """
         classes = []
         for modname, clsname in _MUTAGEN_FORMATS.items():
-            mod = __import__('mutagen.{0}'.format(modname),
+            mod = __import__(b'mutagen.{0}'.format(modname),
                              fromlist=[clsname])
             classes.append(getattr(mod, clsname))
         return classes
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 7041bba13..efe2dc11f 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -78,6 +78,8 @@ Fixes:
 * :doc:`/plugins/importfeeds` and :doc:`/plugins/smartplaylist`: Automatically
   create parent directories for playlist files (instead of crashing when the
   parent directory does not exist). :bug:`1266`
+* The :ref:`write-cmd` command no longer tries to "write" non-writable fields
+  like the bitrate. :bug:`1268`
 
 For developers:
 
diff --git a/test/test_ui.py b/test/test_ui.py
index 6b40d6cca..1fbb8d210 100644
--- a/test/test_ui.py
+++ b/test/test_ui.py
@@ -318,6 +318,37 @@ class WriteTest(unittest.TestCase, TestHelper):
         item = self.lib.items().get()
         self.assertEqual(item.mtime, item.current_mtime())
 
+    def test_non_metadata_field_unchanged(self):
+        """Changing a non-"tag" field like `bitrate` and writing should
+        have no effect.
+        """
+        # An item that starts out "clean".
+        item = self.add_item_fixture()
+        item.read()
+
+        # ... but with a mismatched bitrate.
+        item.bitrate = 123
+        item.store()
+
+        with capture_stdout() as stdout:
+            self.write_cmd()
+
+        self.assertEqual(stdout.getvalue(), '')
+
+    def test_write_metadata_field(self):
+        item = self.add_item_fixture()
+        item.read()
+        old_title = item.title
+
+        item.title = 'new title'
+        item.store()
+
+        with capture_stdout() as stdout:
+            self.write_cmd()
+
+        self.assertTrue('{0} -> new title'.format(old_title)
+                        in stdout.getvalue())
+
 
 class MoveTest(_common.TestCase):
     def setUp(self):
diff --git a/tox.ini b/tox.ini
index c1556533a..a4c2be05d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -17,14 +17,12 @@ deps =
     rarfile
     responses
 commands =
-    nosetests -v {posargs}
+    nosetests {posargs}
 
 [testenv:py26]
 deps =
     {[testenv]deps}
     unittest2
-commands =
-    python ./setup.py test {posargs}
 
 [testenv:py27cov]
 basepython = python2.7
@@ -32,7 +30,12 @@ deps =
     {[testenv]deps}
     coverage
 commands =
-    nosetests -v --with-coverage {posargs}
+    nosetests --with-coverage {posargs}
+
+[testenv:py27setup]
+basepython = python2.7
+commands =
+    python ./setup.py test {posargs}
 
 [testenv:docs]
 changedir = docs