diff --git a/cwMidi.h b/cwMidi.h
index 62f1f9c..73887c4 100644
--- a/cwMidi.h
+++ b/cwMidi.h
@@ -161,6 +161,10 @@ namespace cw
     // of this range will be returned as kInvalidMidiPitch.   
     uint8_t    sciPitchToMidi( const char* sciPitchStr );
 
+    
+#define midi_to_hz( midi_pitch ) (13.75 * std::pow(2,(-9.0/12.0))) * std::pow(2.0,(midi_pitch / 12.0))
+
+
   }
 }