diff --git a/lib/negasonic/looped_event.rb b/lib/negasonic/looped_event.rb
index <HASH>..<HASH> 100644
--- a/lib/negasonic/looped_event.rb
+++ b/lib/negasonic/looped_event.rb
@@ -27,7 +27,7 @@ module Negasonic
             note
           else
             # is a midi note
-            2**((note-69)/12) * 440
+            (2**((note-69)/12) * 440).to_f
           end
         end
       end
use float instaed of rational number