diff --git a/libs/ardour/midi_state_tracker.cc b/libs/ardour/midi_state_tracker.cc
index e3c66e4df8..0ddafc3fed 100644
--- a/libs/ardour/midi_state_tracker.cc
+++ b/libs/ardour/midi_state_tracker.cc
@@ -48,19 +48,18 @@ MidiStateTracker::track_note_onoffs (const Evoral::MIDIEvent<MidiBuffer::TimeTyp
 		}
 	}
 }
+
 void
 MidiStateTracker::add (uint8_t note, uint8_t chn)
 {
-	cerr << "Added note " << note << " chan " << chn << endl;
-	_active_notes[note + 128 * chn]++;
+	++_active_notes[note + 128 * chn];
 }
 
 void
 MidiStateTracker::remove (uint8_t note, uint8_t chn)
 {
 	if (_active_notes[note + 128 * chn]) {
-		cerr << "Removed note " << note << " chan " << chn << endl;
-		_active_notes[note + 128 * chn]--;
+		--_active_notes[note + 128 * chn];
 	}
 }
 
diff --git a/libs/ardour/midi_track.cc b/libs/ardour/midi_track.cc
index 68ff7de1e2..6b27d1b009 100644
--- a/libs/ardour/midi_track.cc
+++ b/libs/ardour/midi_track.cc
@@ -523,17 +523,15 @@ void
 MidiTrack::write_out_of_band_data (BufferSet& bufs, sframes_t /*start*/, sframes_t /*end*/, nframes_t nframes)
 {
 	// Append immediate events
-
 	MidiBuffer& buf (bufs.get_midi (0));
 	_immediate_events.read (buf, 0, 0, nframes - 1); // all stamps = 0
 
-	/* MIDI thru: send incoming data "through" output */
+	// MIDI thru: send incoming data "through" output
 	if (_midi_thru && _input->n_ports().n_midi()) {
 		buf.merge_in_place (_input->midi(0)->get_midi_buffer(nframes));
 	}
 }
 
-
 int
 MidiTrack::export_stuff (BufferSet& /*bufs*/, nframes_t /*nframes*/, sframes_t /*end_frame*/)
 {
diff --git a/libs/ardour/smf_source.cc b/libs/ardour/smf_source.cc
index 169fcaf619..3e35e58fb9 100644
--- a/libs/ardour/smf_source.cc
+++ b/libs/ardour/smf_source.cc
@@ -239,8 +239,8 @@ SMFSource::write_unlocked (MidiRingBuffer<nframes_t>& source, sframes_t position
 		ev.set(buf, size, time);
 		ev.set_event_type(EventTypeMap::instance().midi_event_type(ev.buffer()[0]));
 		if (!(ev.is_channel_event() || ev.is_smf_meta_event() || ev.is_sysex())) {
-			cerr << "SMFSource: WARNING: caller tried to write non SMF-Event of type "
-					<< std::hex << int(ev.buffer()[0]) << endl;
+			/*cerr << "SMFSource: WARNING: caller tried to write non SMF-Event of type "
+					<< std::hex << int(ev.buffer()[0]) << endl;*/
 			continue;
 		}