diff --git a/Sound/Tidal/Pattern.hs b/Sound/Tidal/Pattern.hs
--- a/Sound/Tidal/Pattern.hs
+++ b/Sound/Tidal/Pattern.hs
@@ -55,7 +55,7 @@
 -- | @mappend@ is a synonym for @overlay@.
 instance Monoid (Pattern a) where
     mempty = silence
-    mappend = append
+    mappend = overlay
 
 
 instance Monad Pattern where
diff --git a/tidal.cabal b/tidal.cabal
--- a/tidal.cabal
+++ b/tidal.cabal
@@ -1,5 +1,5 @@
 name:                tidal
-version:             0.3.7
+version:             0.3.8
 synopsis:            Pattern language for improvised music
 -- description:         
 homepage:            http://yaxu.org/tidal/