diff --git a/core/convert.py b/core/convert.py
index 95a4704..5f830a3 100644
--- a/core/convert.py
+++ b/core/convert.py
@@ -18,58 +18,60 @@ https://trac.ffmpeg.org/wiki/Encode/AAC
 def song(input_song, output_song, folder, avconv=False):
     """ Do the audio format conversion. """
     if not input_song == output_song:
+        convert = Converter(input_song, output_song, folder)
         log.info('Converting {0} to {1}'.format(
             input_song, output_song.split('.')[-1]))
         if avconv:
-            exit_code = convert_with_avconv(input_song, output_song, folder)
+            exit_code = convert.with_avconv()
         else:
-            exit_code = convert_with_ffmpeg(input_song, output_song, folder)
+            exit_code = convert.with_ffmpeg()
         return exit_code
     return 0
 
 
-def convert_with_avconv(input_song, output_song, folder):
-    """ Convert the audio file using avconv. """
-    if log.level == 10:
-        level = 'debug'
-    else:
-        level = '0'
+class Converter:
+    def __init__(self, input_song, output_song, folder):
+        self.input_song = input_song
+        self.output_song = output_song
+        self.folder = folder
 
-    command = ['avconv', '-loglevel', level, '-i',
-               os.path.join(folder, input_song), '-ab', '192k',
-               os.path.join(folder, output_song)]
+    def with_avconv(self):
+        if log.level == 10:
+            level = 'debug'
+        else:
+            level = '0'
 
-    log.debug(command)
+        command = ['avconv', '-loglevel', level, '-i',
+                   os.path.join(self.folder, self.input_song), '-ab', '192k',
+                   os.path.join(self.folder, self.output_song)]
 
-    return subprocess.call(command)
+        log.debug(command)
+        return subprocess.call(command)
 
+    def with_ffmpeg(self):
+        ffmpeg_pre = 'ffmpeg -y '
 
-def convert_with_ffmpeg(input_song, output_song, folder):
-    """ Convert the audio file using FFmpeg. """
-    ffmpeg_pre = 'ffmpeg -y '
+        if not log.level == 10:
+            ffmpeg_pre += '-hide_banner -nostats -v panic '
 
-    if not log.level == 10:
-        ffmpeg_pre += '-hide_banner -nostats -v panic '
+        input_ext = self.input_song.split('.')[-1]
+        output_ext = self.output_song.split('.')[-1]
 
-    input_ext = input_song.split('.')[-1]
-    output_ext = output_song.split('.')[-1]
+        if input_ext == 'm4a':
+            if output_ext == 'mp3':
+                ffmpeg_params = '-codec:v copy -codec:a libmp3lame -q:a 2 '
+            elif output_ext == 'webm':
+                ffmpeg_params = '-c:a libopus -vbr on -b:a 192k -vn '
 
-    if input_ext == 'm4a':
-        if output_ext == 'mp3':
-            ffmpeg_params = '-codec:v copy -codec:a libmp3lame -q:a 2 '
-        elif output_ext == 'webm':
-            ffmpeg_params = '-c:a libopus -vbr on -b:a 192k -vn '
+        elif input_ext == 'webm':
+            if output_ext == 'mp3':
+                ffmpeg_params = ' -ab 192k -ar 44100 -vn '
+            elif output_ext == 'm4a':
+                ffmpeg_params = '-cutoff 20000 -c:a libfdk_aac -b:a 192k -vn '
 
-    elif input_ext == 'webm':
-        if output_ext == 'mp3':
-            ffmpeg_params = ' -ab 192k -ar 44100 -vn '
-        elif output_ext == 'm4a':
-            ffmpeg_params = '-cutoff 20000 -c:a libfdk_aac -b:a 192k -vn '
+        command = '{0}-i {1} {2}{3}'.format(
+            ffmpeg_pre, os.path.join(self.folder, self.input_song),
+            ffmpeg_params, os.path.join(self.folder, self.output_song)).split(' ')
 
-    command = '{0}-i {1} {2}{3}'.format(
-        ffmpeg_pre, os.path.join(folder, input_song),
-        ffmpeg_params, os.path.join(folder, output_song)).split(' ')
-
-    log.debug(command)
-
-    return subprocess.call(command)
+        log.debug(command)
+        return subprocess.call(command)
diff --git a/core/metadata.py b/core/metadata.py
index e7b795f..829fea6 100755
--- a/core/metadata.py
+++ b/core/metadata.py
@@ -8,7 +8,6 @@ import urllib.request
 
 def compare(music_file, metadata):
     """Check if the input music file title matches the expected title."""
-    already_tagged = False
     try:
         if music_file.endswith('.mp3'):
             audiofile = EasyID3(music_file)
@@ -17,29 +16,31 @@ def compare(music_file, metadata):
             audiofile = MP4(music_file)
             already_tagged = audiofile[tags['title']] == metadata['name']
     except (KeyError, TypeError):
-        pass
+        already_tagged = False
+
     return already_tagged
 
 
 def embed(music_file, meta_tags):
     """ Embed metadata. """
-    embedder = EmbedMetadata(music_file, meta_tags)
+    embed = EmbedMetadata(music_file, meta_tags)
     if music_file.endswith('.m4a'):
         log.info('Applying metadata')
-        return embedder.m4a()
+        return embed.as_m4a()
     elif music_file.endswith('.mp3'):
         log.info('Applying metadata')
-        return embedder.mp3()
+        return embed.as_mp3()
     else:
         log.warning('Cannot embed metadata into given output extension')
         return False
 
+
 class EmbedMetadata:
     def __init__(self, music_file, meta_tags):
         self.music_file = music_file
         self.meta_tags = meta_tags
 
-    def mp3(self):
+    def as_mp3(self):
         """ Embed metadata to MP3 files. """
         music_file = self.music_file
         meta_tags = self.meta_tags
@@ -81,7 +82,7 @@ class EmbedMetadata:
         audiofile.save(v2_version=3)
         return True
 
-    def m4a(self):
+    def as_m4a(self):
         """ Embed metadata to M4A files. """
         music_file = self.music_file
         meta_tags = self.meta_tags