+#ifndef VOICE_CHANGE_SONG
+ #define VOICE_CHANGE_SONG SONG(VOICE_CHANGE_SOUND)
+#endif
+float voice_change_song[][2] = VOICE_CHANGE_SONG;
+
+#ifndef PITCH_STANDARD_A
+ #define PITCH_STANDARD_A 440.0f
+#endif
+
+float compute_freq_for_midi_note(uint8_t note)