+class Midi_duration : public Midi_item
+{
+public:
+ Midi_duration (Real seconds_f);
+
+ virtual string to_string () const;
+ Real seconds_;
+};
+
+
+/**
+ Change instrument event
+*/
+class Midi_instrument : public Midi_channel_item
+{
+public:
+ Midi_instrument (Audio_instrument *);
+
+ DECLARE_CLASSNAME(Midi_instrument);
+ virtual string to_string () const;
+
+ Audio_instrument *audio_;
+};