diff --git a/beets/dbcore/types.py b/beets/dbcore/types.py
index 4862d39b4..06bd397fe 100644
--- a/beets/dbcore/types.py
+++ b/beets/dbcore/types.py
@@ -14,6 +14,8 @@
 
 """Representation of type information for DBCore model fields.
 """
+import re
+
 from . import query
 from beets.util import str2bool
 
@@ -164,3 +166,31 @@ class Boolean(Type):
 
     def parse(self, string):
         return str2bool(string)
+
+
+class MusicalKey(String):
+    """String representing the musical key of a song.
+
+    The standard format is C, Cm, C#, C#m, etc.
+    """
+
+    ENHARMONIC = {
+        r'db': 'c#',
+        r'eb': 'd#',
+        r'gb': 'f#',
+        r'ab': 'g#',
+        r'bb': 'a#',
+    }
+
+    def parse(self, key):
+        key = key.lower()
+        for flat, sharp in self.ENHARMONIC:
+            re.sub(flat, sharp, key)
+        re.sub(r'[\W\s]+minor', 'm', key)
+        return key.capitalize()
+
+    def normalize(self, key):
+        if key is None:
+            return None
+        else:
+            return self.parse(key)
diff --git a/beets/library.py b/beets/library.py
index ca5ece778..574ce85e7 100644
--- a/beets/library.py
+++ b/beets/library.py
@@ -252,6 +252,7 @@ class Item(LibModel):
         'original_year':        types.PaddedInt(4),
         'original_month':       types.PaddedInt(2),
         'original_day':         types.PaddedInt(2),
+        'initial_key':          types.MusicalKey(),
 
         'length':      types.Float(),
         'bitrate':     types.ScaledInt(1000, u'kbps'),
diff --git a/beets/mediafile.py b/beets/mediafile.py
index b4414f244..a05fb5414 100644
--- a/beets/mediafile.py
+++ b/beets/mediafile.py
@@ -1752,6 +1752,13 @@ class MediaFile(object):
         out_type=float,
     )
 
+    initial_key = MediaField(
+        MP3StorageStyle('TKEY'),
+        MP4StorageStyle('----:com.apple.iTunes:initialkey'),
+        StorageStyle('INITIALKEY'),
+        ASFStorageStyle('INITIALKEY'),
+    )
+
     @property
     def length(self):
         """The duration of the audio in seconds (a float)."""
diff --git a/beetsplug/echonest.py b/beetsplug/echonest.py
index 8b6509a55..8c92a7b8e 100644
--- a/beetsplug/echonest.py
+++ b/beetsplug/echonest.py
@@ -47,6 +47,11 @@ ATTRIBUTES = {
     'valence':      'valence',
     'tempo':        'bpm',
 }
+
+MUSICAL_SCALE = ['C', 'C#', 'D', 'D#', 'E' 'F',
+                 'F#', 'G', 'G#', 'A', 'A#', 'B']
+
+
 # We also use echonest_id (song_id) and echonest_fingerprint to speed up
 # lookups.
 ID_KEY = 'echonest_id'
@@ -407,6 +412,11 @@ class EchonestMetadataPlugin(plugins.BeetsPlugin):
                     item[field] = int(v)
                 else:
                     item[field] = v
+        if 'key' in values and 'mode' in values:
+            key = MUSICAL_SCALE[values['key'] - 1]
+            if values['mode'] == 0:  # Minor key
+                key += 'm'
+            item['initial_key'] = key
         if 'id' in values:
             enid = values['id']
             log.debug(u'echonest: metadata: {0} = {1}'.format(ID_KEY, enid))
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 9366bbf9a..bd134609e 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -13,6 +13,11 @@ New stuff:
 * :doc:`/plugins/replaygain`: Added support for calculating ReplayGain values
   with GStreamer as well the mp3gain programs. This enables ReplayGain
   calculation for any audio format.
+* Add support for `initial_key` as field in the library and tag for
+  media files. When the user sets this field with ``beet modify
+  initial_key=Am`` the media files will reflect this in their tags. The
+  :doc:`/plugins/echonest` plugin also sets this field if the data is
+  available.
 
 Fixes:
 
diff --git a/setup.py b/setup.py
index 04f3959f7..e2c917121 100755
--- a/setup.py
+++ b/setup.py
@@ -86,6 +86,8 @@ setup(
 
     tests_require=[
         'responses',
+        'pyechonest',
+        'mock',
     ],
 
     # Plugin (optional) dependencies:
diff --git a/test/test_echonest.py b/test/test_echonest.py
new file mode 100644
index 000000000..e0f044a71
--- /dev/null
+++ b/test/test_echonest.py
@@ -0,0 +1,79 @@
+# This file is part of beets.
+# Copyright 2014, Thomas Scholtes
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# 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.
+
+
+import os.path
+from mock import Mock, patch
+
+import _common
+from _common import unittest
+from helper import TestHelper
+
+from beets.library import Item, Album
+
+
+class EchonestCliTest(unittest.TestCase, TestHelper):
+
+    def setUp(self):
+        self.setup_beets()
+        self.load_plugins('echonest')
+
+    def tearDown(self):
+        self.teardown_beets()
+        self.unload_plugins()
+
+    @patch.object(Item, 'write')
+    @patch('pyechonest.song.profile')
+    @patch('pyechonest.track.track_from_id')
+    def test_store_data(self, echonest_track, echonest_profile, item_write):
+        profile = Mock(
+            artist_name='artist',
+            title='title',
+            id='echonestid',
+            audio_summary={
+                'duration': 10,
+                'energy': 0.5,
+                'liveness': 0.5,
+                'loudness': 0.5,
+                'speechiness': 0.5,
+                'danceability': 0.5,
+                'tempo': 120,
+                'key': 2,
+                'mode': 0
+            },
+        )
+        echonest_profile.return_value = [profile]
+        echonest_track.return_value = Mock(song_id='echonestid')
+
+        item = Item(
+            mb_trackid='01234',
+            artist='artist',
+            title='title',
+            length=10,
+        )
+        item.add(self.lib)
+        self.assertNotIn('danceability', item)
+        self.assertNotIn('initialkey', item)
+
+        self.run_command('echonest')
+        item.load()
+        self.assertEqual(item['danceability'], '0.5')
+        self.assertEqual(item['initial_key'], 'C#m')
+
+
+def suite():
+    return unittest.TestLoader().loadTestsFromName(__name__)
+
+if __name__ == '__main__':
+    unittest.main(defaultTest='suite')
diff --git a/test/test_mediafile.py b/test/test_mediafile.py
index 060f7cf2c..10f22f09b 100644
--- a/test/test_mediafile.py
+++ b/test/test_mediafile.py
@@ -24,7 +24,7 @@ import time
 import _common
 from _common import unittest
 from beets.mediafile import MediaFile, MediaField, Image, \
-                            MP3StorageStyle, StorageStyle, \
+                            MP3DescStorageStyle, StorageStyle, \
                             MP4StorageStyle, ASFStorageStyle, \
                             ImageType
 from beets.library import Item
@@ -259,54 +259,54 @@ class GenreListTestMixin(object):
 
 
 field_extension = MediaField(
-    MP3StorageStyle('TKEY'),
-    MP4StorageStyle('----:com.apple.iTunes:initialkey'),
-    StorageStyle('INITIALKEY'),
-    ASFStorageStyle('INITIALKEY'),
+    MP3DescStorageStyle('customtag'),
+    MP4StorageStyle('----:com.apple.iTunes:customtag'),
+    StorageStyle('customtag'),
+    ASFStorageStyle('customtag'),
 )
 class ExtendedFieldTestMixin(object):
 
     def test_extended_field_write(self):
         plugin = BeetsPlugin()
-        plugin.add_media_field('initialkey', field_extension)
+        plugin.add_media_field('customtag', field_extension)
 
         mediafile = self._mediafile_fixture('empty')
-        mediafile.initialkey = 'F#'
+        mediafile.customtag = 'F#'
         mediafile.save()
 
         mediafile = MediaFile(mediafile.path)
-        self.assertEqual(mediafile.initialkey, 'F#')
-        delattr(MediaFile, 'initialkey')
-        Item._media_fields.remove('initialkey')
+        self.assertEqual(mediafile.customtag, 'F#')
+        delattr(MediaFile, 'customtag')
+        Item._media_fields.remove('customtag')
 
     def test_write_extended_tag_from_item(self):
         plugin = BeetsPlugin()
-        plugin.add_media_field('initialkey', field_extension)
+        plugin.add_media_field('customtag', field_extension)
 
         mediafile = self._mediafile_fixture('empty')
-        self.assertIsNone(mediafile.initialkey)
+        self.assertIsNone(mediafile.customtag)
 
-        item = Item(path=mediafile.path, initialkey='Gb')
+        item = Item(path=mediafile.path, customtag='Gb')
         item.write()
         mediafile = MediaFile(mediafile.path)
-        self.assertEqual(mediafile.initialkey, 'Gb')
+        self.assertEqual(mediafile.customtag, 'Gb')
 
-        delattr(MediaFile, 'initialkey')
-        Item._media_fields.remove('initialkey')
+        delattr(MediaFile, 'customtag')
+        Item._media_fields.remove('customtag')
 
     def test_read_flexible_attribute_from_file(self):
         plugin = BeetsPlugin()
-        plugin.add_media_field('initialkey', field_extension)
+        plugin.add_media_field('customtag', field_extension)
 
         mediafile = self._mediafile_fixture('empty')
-        mediafile.update({'initialkey': 'F#'})
+        mediafile.update({'customtag': 'F#'})
         mediafile.save()
 
         item = Item.from_path(mediafile.path)
-        self.assertEqual(item['initialkey'], 'F#')
+        self.assertEqual(item['customtag'], 'F#')
 
-        delattr(MediaFile, 'initialkey')
-        Item._media_fields.remove('initialkey')
+        delattr(MediaFile, 'customtag')
+        Item._media_fields.remove('customtag')
 
     def test_invalid_descriptor(self):
         with self.assertRaises(ValueError) as cm:
@@ -401,6 +401,7 @@ class ReadWriteTestBase(ArtTestMixin, GenreListTestMixin,
         'original_month',
         'original_day',
         'original_date',
+        'initial_key',
     ]
 
     def setUp(self):
diff --git a/test/test_ui.py b/test/test_ui.py
index 2f8edf3ec..ce72debd0 100644
--- a/test/test_ui.py
+++ b/test/test_ui.py
@@ -154,10 +154,10 @@ class ModifyTest(_common.TestCase):
         self.lib = library.Library(':memory:', self.libdir)
         self.i = library.Item.from_path(os.path.join(_common.RSRC, 'full.mp3'))
         self.lib.add(self.i)
-        self.i.move(True)
+        self.i.move(copy=True)
         self.album = self.lib.add_album([self.i])
 
-    def _modify(self, mods, dels=(), query=(), write=False, move=False,
+    def _modify(self, mods=(), dels=(), query=(), write=False, move=False,
                 album=False):
         self.io.addinput('y')
         commands.modify_items(self.lib, mods, dels, query,
@@ -219,6 +219,26 @@ class ModifyTest(_common.TestCase):
         item.read()
         self.assertFalse('newAlbum' in item.path)
 
+    def test_write_initial_key_tag(self):
+        self._modify(["initial_key=C#m"], write=True)
+        item = self.lib.items().get()
+        mediafile = MediaFile(item.path)
+        self.assertEqual(mediafile.initial_key, 'C#m')
+
+    @unittest.skip('not yet implemented')
+    def test_delete_initial_key_tag(self):
+        item = self.i
+        item.initial_key = 'C#m'
+        item.write()
+        item.store()
+
+        mediafile = MediaFile(item.path)
+        self.assertEqual(mediafile.initial_key, 'C#m')
+
+        self._modify(dels=["initial_key!"], write=True)
+        mediafile = MediaFile(item.path)
+        self.assertIsNone(mediafile.initial_key)
+
 class MoveTest(_common.TestCase):
     def setUp(self):
         super(MoveTest, self).setUp()
diff --git a/tox.ini b/tox.ini
index d4d056f94..5e50071c6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -9,9 +9,11 @@ envlist = py26, py27, pypy, docs, flake8
 [testenv]
 deps =
     nose
+    mock
     pylast
     flask
     responses
+    pyechonest
 commands =
     nosetests {posargs}