diff --git a/spotipy/client.py b/spotipy/client.py
index 3a63bb0..5e13611 100644
--- a/spotipy/client.py
+++ b/spotipy/client.py
@@ -709,13 +709,13 @@ class Spotify(object):
         '''
         params = dict(limit=limit)
         if seed_artists:
-            params['seed_artists'] = [self._get_id('artist', a)
-                                      for a in seed_artists]
+            params['seed_artists'] = ','.join(
+                [self._get_id('artist', a) for a in seed_artists])
         if seed_genres:
-            params['seed_genres'] = seed_genres
+            params['seed_genres'] = ','.join(seed_genres)
         if seed_tracks:
-            params['seed_tracks'] = [self._get_id('track', t)
-                                     for t in seed_tracks]
+            params['seed_tracks'] = ','.join(
+                [self._get_id('track', t) for t in seed_tracks])
         if country:
             params['market'] = country