diff --git a/libs/surfaces/cc121/cc121.cc b/libs/surfaces/cc121/cc121.cc
index de14e1e96a..18d64a5daf 100644
--- a/libs/surfaces/cc121/cc121.cc
+++ b/libs/surfaces/cc121/cc121.cc
@@ -1052,8 +1052,8 @@ void
 CC121::drop_current_stripable ()
 {
 	if (_current_stripable) {
-		if (_current_stripable == _session->monitor_out()) {
-			set_current_stripable (_session->master_out());
+		if (_current_stripable == monitor_out ()) {
+			set_current_stripable (master_out ());
 		} else {
 			set_current_stripable (boost::shared_ptr<Stripable>());
 		}
@@ -1255,7 +1255,7 @@ CC121::map_stripable_state ()
 		map_auto ();
 		map_monitoring ();
 
-		if (_current_stripable == _session->monitor_out()) {
+		if (_current_stripable == monitor_out ()) {
 			map_cut ();
 		} else {
 			map_mute ();
diff --git a/libs/surfaces/cc121/operations.cc b/libs/surfaces/cc121/operations.cc
index 1078db4ef1..edbdf1cbba 100644
--- a/libs/surfaces/cc121/operations.cc
+++ b/libs/surfaces/cc121/operations.cc
@@ -157,7 +157,7 @@ CC121::mute ()
 		return;
 	}
 
-	if (_current_stripable == _session->monitor_out()) {
+	if (_current_stripable == monitor_out ()) {
 		boost::shared_ptr<MonitorProcessor> mp = _current_stripable->monitor_control();
 		mp->set_cut_all (!mp->cut_all());
 		return;
@@ -194,7 +194,7 @@ CC121::rec_enable ()
 void
 CC121::use_master ()
 {
-	boost::shared_ptr<Stripable> r = _session->master_out();
+	boost::shared_ptr<Stripable> r = master_out ();
 	if (r) {
 		if (_current_stripable == r) {
 			r = pre_master_stripable.lock();
@@ -202,7 +202,7 @@ CC121::use_master ()
 			get_button(Output).set_led_state (_output_port, false);
 			blinkers.remove (Output);
 		} else {
-			if (_current_stripable != _session->master_out() && _current_stripable != _session->monitor_out()) {
+			if (_current_stripable != master_out () && _current_stripable != monitor_out ()) {
 				pre_master_stripable = boost::weak_ptr<Stripable> (_current_stripable);
 			}
 			set_current_stripable (r);
@@ -215,7 +215,7 @@ CC121::use_master ()
 void
 CC121::use_monitor ()
 {
-	boost::shared_ptr<Stripable> r = _session->monitor_out();
+	boost::shared_ptr<Stripable> r = monitor_out ();
 
 	if (r) {
 		if (_current_stripable == r) {
@@ -224,7 +224,7 @@ CC121::use_monitor ()
 			get_button(Output).set_led_state (_output_port, false);
 			blinkers.remove (Output);
 		} else {
-			if (_current_stripable != _session->master_out() && _current_stripable != _session->monitor_out()) {
+			if (_current_stripable != master_out () && _current_stripable != monitor_out ()) {
 				pre_monitor_stripable = boost::weak_ptr<Stripable> (_current_stripable);
 			}
 			set_current_stripable (r);
diff --git a/libs/surfaces/control_protocol/basic_ui.cc b/libs/surfaces/control_protocol/basic_ui.cc
index a5317ff603..887d808a09 100644
--- a/libs/surfaces/control_protocol/basic_ui.cc
+++ b/libs/surfaces/control_protocol/basic_ui.cc
@@ -828,3 +828,15 @@ BasicUI::config ()
 {
 	return _session->config;
 }
+
+boost::shared_ptr<Stripable>
+BasicUI::monitor_out () const
+{
+	return _session->monitor_out ();
+}
+
+boost::shared_ptr<Stripable>
+BasicUI::master_out () const
+{
+	return _session->master_out ();
+}
diff --git a/libs/surfaces/control_protocol/control_protocol/basic_ui.h b/libs/surfaces/control_protocol/control_protocol/basic_ui.h
index d60a43118b..6240427b40 100644
--- a/libs/surfaces/control_protocol/control_protocol/basic_ui.h
+++ b/libs/surfaces/control_protocol/control_protocol/basic_ui.h
@@ -38,6 +38,7 @@
 
 namespace ARDOUR {
 
+class Route;
 class Session;
 class SessionConfiguration;
 
@@ -172,6 +173,11 @@ class LIBCONTROLCP_API BasicUI {
 	const SessionConfiguration& config () const;
 	SessionConfiguration&       config ();
 
+	/* Monitor/Master Out */
+
+	boost::shared_ptr<Stripable> monitor_out () const;
+	boost::shared_ptr<Stripable> master_out () const;
+
   protected:
 	Session* _session;
 };
diff --git a/libs/surfaces/faderport/faderport.cc b/libs/surfaces/faderport/faderport.cc
index d9dd34bbf8..da7a0150dc 100644
--- a/libs/surfaces/faderport/faderport.cc
+++ b/libs/surfaces/faderport/faderport.cc
@@ -1096,8 +1096,8 @@ void
 FaderPort::drop_current_stripable ()
 {
 	if (_current_stripable) {
-		if (_current_stripable == _session->monitor_out()) {
-			set_current_stripable (_session->master_out());
+		if (_current_stripable == monitor_out ()) {
+			set_current_stripable (master_out ());
 		} else {
 			set_current_stripable (boost::shared_ptr<Stripable>());
 		}
@@ -1299,7 +1299,7 @@ FaderPort::map_stripable_state ()
 		map_gain ();
 		map_auto ();
 
-		if (_current_stripable == _session->monitor_out()) {
+		if (_current_stripable == monitor_out ()) {
 			map_cut ();
 		} else {
 			map_mute ();
diff --git a/libs/surfaces/faderport/operations.cc b/libs/surfaces/faderport/operations.cc
index 7d7e8a0d86..ea80fd38c7 100644
--- a/libs/surfaces/faderport/operations.cc
+++ b/libs/surfaces/faderport/operations.cc
@@ -124,7 +124,7 @@ FaderPort::mute ()
 		return;
 	}
 
-	if (_current_stripable == _session->monitor_out()) {
+	if (_current_stripable == monitor_out ()) {
 		boost::shared_ptr<MonitorProcessor> mp = _current_stripable->monitor_control();
 		mp->set_cut_all (!mp->cut_all());
 		return;
@@ -162,7 +162,7 @@ FaderPort::rec_enable ()
 void
 FaderPort::use_master ()
 {
-	boost::shared_ptr<Stripable> r = _session->master_out();
+	boost::shared_ptr<Stripable> r = master_out ();
 	if (r) {
 		if (_current_stripable == r) {
 			r = pre_master_stripable.lock();
@@ -170,7 +170,7 @@ FaderPort::use_master ()
 			get_button(Output).set_led_state (_output_port, false);
 			blinkers.remove (Output);
 		} else {
-			if (_current_stripable != _session->master_out() && _current_stripable != _session->monitor_out()) {
+			if (_current_stripable != master_out () && _current_stripable != monitor_out ()) {
 				pre_master_stripable = boost::weak_ptr<Stripable> (_current_stripable);
 			}
 			set_current_stripable (r);
@@ -183,7 +183,7 @@ FaderPort::use_master ()
 void
 FaderPort::use_monitor ()
 {
-	boost::shared_ptr<Stripable> r = _session->monitor_out();
+	boost::shared_ptr<Stripable> r = monitor_out ();
 
 	if (r) {
 		if (_current_stripable == r) {
@@ -192,7 +192,7 @@ FaderPort::use_monitor ()
 			get_button(Output).set_led_state (_output_port, false);
 			blinkers.remove (Output);
 		} else {
-			if (_current_stripable != _session->master_out() && _current_stripable != _session->monitor_out()) {
+			if (_current_stripable != master_out () && _current_stripable != monitor_out ()) {
 				pre_monitor_stripable = boost::weak_ptr<Stripable> (_current_stripable);
 			}
 			set_current_stripable (r);
diff --git a/libs/surfaces/faderport8/actions.cc b/libs/surfaces/faderport8/actions.cc
index 258db5b1b2..476a48b5c6 100644
--- a/libs/surfaces/faderport8/actions.cc
+++ b/libs/surfaces/faderport8/actions.cc
@@ -549,9 +549,9 @@ FaderPort8::button_encoder ()
 				/* master || monitor level -- reset to 0dB */
 				boost::shared_ptr<AutomationControl> ac;
 				if (_session->monitor_active() && !_ctrls.button (FP8Controls::BtnMaster).is_pressed ()) {
-					ac = _session->monitor_out()->gain_control ();
-				} else if (_session->master_out()) {
-					ac = _session->master_out()->gain_control ();
+					ac = monitor_out ()->gain_control ();
+				} else if (master_out ()) {
+					ac = master_out ()->gain_control ();
 				}
 				if (ac) {
 					ac->start_touch (timepos_t (transport_sample()));
@@ -629,9 +629,9 @@ FaderPort8::encoder_navigate (bool neg, int steps)
 				/* master || monitor level */
 				boost::shared_ptr<AutomationControl> ac;
 				if (_session->monitor_active() && !_ctrls.button (FP8Controls::BtnMaster).is_pressed ()) {
-					ac = _session->monitor_out()->gain_control ();
-				} else if (_session->master_out()) {
-					ac = _session->master_out()->gain_control ();
+					ac = monitor_out ()->gain_control ();
+				} else if (master_out ()) {
+					ac = master_out ()->gain_control ();
 				}
 				if (ac) {
 					double v = ac->internal_to_interface (ac->get_value());
diff --git a/libs/surfaces/generic_midi/generic_midi_control_protocol.cc b/libs/surfaces/generic_midi/generic_midi_control_protocol.cc
index fb52801808..15d6bdc836 100644
--- a/libs/surfaces/generic_midi/generic_midi_control_protocol.cc
+++ b/libs/surfaces/generic_midi/generic_midi_control_protocol.cc
@@ -1116,9 +1116,9 @@ GenericMidiControlProtocol::lookup_controllable (const string & str) const
 			name = rest[0];
 
 			if (name == "Master" || name == X_("master")) {
-				s = _session->master_out();
+				s = master_out ();
 			} else if (name == X_("control") || name == X_("listen") || name == X_("monitor") || name == "Monitor") {
-				s = _session->monitor_out();
+				s = monitor_out ();
 			} else if (name == X_("auditioner")) {
 				s = _session->the_auditioner();
 			} else {
diff --git a/libs/surfaces/launch_control_xl/launch_control_xl.cc b/libs/surfaces/launch_control_xl/launch_control_xl.cc
index e849d1e7dc..6fb15c9bfa 100644
--- a/libs/surfaces/launch_control_xl/launch_control_xl.cc
+++ b/libs/surfaces/launch_control_xl/launch_control_xl.cc
@@ -94,7 +94,7 @@ LaunchControlXL::LaunchControlXL (ARDOUR::Session& s)
 	/* we're going to need this */
 
 	/* master cannot be removed, so no need to connect to going-away signal */
-	master = _session->master_out ();
+	master = master_out ();
 
 	run_event_loop ();
 
diff --git a/libs/surfaces/mackie/mackie_control_protocol.cc b/libs/surfaces/mackie/mackie_control_protocol.cc
index 6e3890b431..ab4189f1f0 100644
--- a/libs/surfaces/mackie/mackie_control_protocol.cc
+++ b/libs/surfaces/mackie/mackie_control_protocol.cc
@@ -1843,13 +1843,13 @@ MackieControlProtocol::set_flip_mode (FlipMode fm)
 void
 MackieControlProtocol::set_master_on_surface_strip (uint32_t surface, uint32_t strip_number)
 {
-	force_special_stripable_to_strip (_session->master_out(), surface, strip_number);
+	force_special_stripable_to_strip (master_out (), surface, strip_number);
 }
 
 void
 MackieControlProtocol::set_monitor_on_surface_strip (uint32_t surface, uint32_t strip_number)
 {
-	force_special_stripable_to_strip (_session->monitor_out(), surface, strip_number);
+	force_special_stripable_to_strip (monitor_out (), surface, strip_number);
 }
 
 void
@@ -1865,7 +1865,7 @@ MackieControlProtocol::force_special_stripable_to_strip (boost::shared_ptr<Strip
 		if ((*s)->number() == surface) {
 			Strip* strip = (*s)->nth_strip (strip_number);
 			if (strip) {
-				strip->set_stripable (_session->master_out());
+				strip->set_stripable (master_out ());
 				strip->lock_controls ();
 			}
 		}
diff --git a/libs/surfaces/mackie/surface.cc b/libs/surfaces/mackie/surface.cc
index 48db725bd6..311b94aabd 100644
--- a/libs/surfaces/mackie/surface.cc
+++ b/libs/surfaces/mackie/surface.cc
@@ -413,8 +413,8 @@ Surface::master_monitor_may_have_changed ()
 void
 Surface::setup_master ()
 {
-	if ((_master_stripable = _mcp.get_session().monitor_out()) == 0) {
-		_master_stripable = _mcp.get_session().master_out();
+	if ((_master_stripable = _mcp.monitor_out()) == 0) {
+		_master_stripable = _mcp.master_out();
 	}
 
 	if (!_master_stripable) {
diff --git a/libs/surfaces/maschine2/callbacks.cc b/libs/surfaces/maschine2/callbacks.cc
index 5f8e9ed4e9..1703ef776e 100644
--- a/libs/surfaces/maschine2/callbacks.cc
+++ b/libs/surfaces/maschine2/callbacks.cc
@@ -362,7 +362,7 @@ Maschine2::encoder_master (int delta)
 			break;
 		case MST_VOLUME:
 			{
-				boost::shared_ptr<Route> master = _session->master_out ();
+				boost::shared_ptr<Stripable> master = master_out ();
 				if (master) {
 					// TODO consider _ctrl->button (M2Contols::EncoderWheel)->is_pressed() for fine grained
 					const double factor = _ctrl->button (M2Contols::BtnShift, M2Contols::ModNone)->active () ? 256. : 32.;
diff --git a/libs/surfaces/maschine2/maschine2.cc b/libs/surfaces/maschine2/maschine2.cc
index d2008a8bad..47e53be0c3 100644
--- a/libs/surfaces/maschine2/maschine2.cc
+++ b/libs/surfaces/maschine2/maschine2.cc
@@ -77,8 +77,8 @@ class TestLayout : public Maschine2Layout
 
 			knob = new Maschine2Knob(&m2, this);
 			knob->set_position (Duple (64 + 32, 32));
-			if (_session.master_out ()) {
-				knob->set_controllable (_session.master_out ()->gain_control());
+			if (m2.master_out ()) {
+				knob->set_controllable (m2.master_out ()->gain_control());
 			}
 
 			std::vector<std::string> strs;
diff --git a/libs/surfaces/osc/osc.cc b/libs/surfaces/osc/osc.cc
index 0b9b56d081..5697240cfc 100644
--- a/libs/surfaces/osc/osc.cc
+++ b/libs/surfaces/osc/osc.cc
@@ -276,7 +276,7 @@ OSC::start ()
 
 	_select = ControlProtocol::first_selected_stripable();
 	if(!_select) {
-		_select = _session->master_out ();
+		_select = master_out ();
 	}
 
 	return 0;
@@ -1116,7 +1116,7 @@ OSC::routes_list (lo_message msg)
 	lo_message_add_string (reply, X_("end_route_list"));
 	lo_message_add_int64 (reply, _session->sample_rate());
 	lo_message_add_int64 (reply, _session->current_end_sample());
-	if (_session->monitor_out()) {
+	if (monitor_out ()) {
 		// this session has a monitor section
 		lo_message_add_int32 (reply, 1);
 	} else {
@@ -3368,7 +3368,7 @@ OSC::master_parse (const char *path, const char* types, lo_arg **argv, int argc,
 	}
 
 	//OSCSurface *sur = get_surface(get_address (msg));
-	boost::shared_ptr<Stripable> s = _session->master_out();
+	boost::shared_ptr<Stripable> s = master_out();
 	if (s) {
 		ret = _strip_parse (path, sub_path, types, argv, argc, s, 0, false, msg);
 	} else {
@@ -3395,9 +3395,9 @@ OSC::monitor_parse (const char *path, const char* types, lo_arg **argv, int argc
 	}
 
 	//OSCSurface *sur = get_surface(get_address (msg));
-	boost::shared_ptr<Stripable> s = _session->monitor_out();
+	boost::shared_ptr<Stripable> s = monitor_out ();
 	if (s) {
-		boost::shared_ptr<MonitorProcessor> mon = _session->monitor_out()->monitor_control();
+		boost::shared_ptr<MonitorProcessor> mon = monitor_out ()->monitor_control();
 		int state = 0;
 		if (types[0] == 'f') {
 			state = (uint32_t) argv[0]->f;
@@ -4714,7 +4714,7 @@ OSC::_strip_select2 (boost::shared_ptr<Stripable> s, OSCSurface *sur, lo_address
 		if (ControlProtocol::first_selected_stripable()) {
 			s = ControlProtocol::first_selected_stripable();
 		} else {
-			s = _session->master_out ();
+			s = master_out ();
 		}
 		_select = s;
 	}
@@ -6126,13 +6126,13 @@ OSC::get_sorted_stripables(std::bitset<32> types, bool cue, uint32_t custom, Sor
 	if (!custom) {
 		// Master/Monitor might be anywhere... we put them at the end - Sorry ;)
 		if (types[5]) {
-			if (_session->master_out()) {
-				sorted.push_back (_session->master_out());
+			if (master_out ()) {
+				sorted.push_back (master_out());
 			}
 		}
 		if (types[6]) {
-			if (_session->monitor_out()) {
-				sorted.push_back (_session->monitor_out());
+			if (monitor_out ()) {
+				sorted.push_back (monitor_out ());
 			}
 		}
 	}
diff --git a/libs/surfaces/osc/osc_global_observer.cc b/libs/surfaces/osc/osc_global_observer.cc
index 7cbc26be5e..c3606fc4cc 100644
--- a/libs/surfaces/osc/osc_global_observer.cc
+++ b/libs/surfaces/osc/osc_global_observer.cc
@@ -67,7 +67,7 @@ OSCGlobalObserver::OSCGlobalObserver (OSC& o, Session& s, ArdourSurface::OSC::OS
 
 		// Master channel first
 		_osc.text_message (X_("/master/name"), "Master", addr);
-		boost::shared_ptr<Stripable> strip = session->master_out();
+		boost::shared_ptr<Stripable> strip = _osc.master_out ();
 
 		boost::shared_ptr<Controllable> mute_controllable = boost::dynamic_pointer_cast<Controllable>(strip->mute_control());
 		mute_controllable->Changed.connect (strip_connections, MISSING_INVALIDATOR, boost::bind (&OSCGlobalObserver::send_change_message, this, X_("/master/mute"), strip->mute_control()), OSC::instance());
@@ -88,7 +88,7 @@ OSCGlobalObserver::OSCGlobalObserver (OSC& o, Session& s, ArdourSurface::OSC::OS
 		send_gain_message (X_("/master/"), gain_controllable);
 
 		// monitor stuff next
-		strip = session->monitor_out();
+		strip = _osc.monitor_out();
 		if (strip) {
 			_osc.text_message (X_("/monitor/name"), "Monitor", addr);
 
@@ -301,7 +301,7 @@ OSCGlobalObserver::tick ()
 	}
 	if (feedback[7] || feedback[8] || feedback[9]) { // meters enabled
 		// the only meter here is master
-		float now_meter = session->master_out()->peak_meter()->meter_level(0, MeterMCP);
+		float now_meter = _osc.master_out()->peak_meter()->meter_level(0, MeterMCP);
 		if (now_meter < -94) now_meter = -193;
 		if (_last_meter != now_meter) {
 			if (feedback[7] || feedback[8]) {
diff --git a/libs/surfaces/osc/osc_route_observer.cc b/libs/surfaces/osc/osc_route_observer.cc
index 5b2ba2dfdc..c627e02693 100644
--- a/libs/surfaces/osc/osc_route_observer.cc
+++ b/libs/surfaces/osc/osc_route_observer.cc
@@ -25,7 +25,6 @@
 #include <glibmm.h>
 
 
-#include "ardour/session.h"
 #include "ardour/track.h"
 #include "ardour/monitor_control.h"
 #include "ardour/dB.h"
diff --git a/libs/surfaces/push2/buttons.cc b/libs/surfaces/push2/buttons.cc
index 5e506cf83c..4932fae752 100644
--- a/libs/surfaces/push2/buttons.cc
+++ b/libs/surfaces/push2/buttons.cc
@@ -739,7 +739,7 @@ Push2::button_mix_press ()
 void
 Push2::button_master ()
 {
-	boost::shared_ptr<Stripable> main_out = _session->master_out ();
+	boost::shared_ptr<Stripable> main_out = master_out ();
 
 	if (!main_out) {
 		return;
diff --git a/libs/surfaces/push2/push2.cc b/libs/surfaces/push2/push2.cc
index abe1c566b9..579963c555 100644
--- a/libs/surfaces/push2/push2.cc
+++ b/libs/surfaces/push2/push2.cc
@@ -108,7 +108,7 @@ Push2::Push2 (ARDOUR::Session& s)
 	fill_color_table ();
 
 	/* master cannot be removed, so no need to connect to going-away signal */
-	master = _session->master_out ();
+	master = master_out ();
 
 	/* allocate graphics layouts, even though we're not using them yet */
 
diff --git a/libs/surfaces/us2400/mcp_buttons.cc b/libs/surfaces/us2400/mcp_buttons.cc
index 46d7eb376c..8673ae2f31 100644
--- a/libs/surfaces/us2400/mcp_buttons.cc
+++ b/libs/surfaces/us2400/mcp_buttons.cc
@@ -772,7 +772,7 @@ LedState
 US2400Protocol::mstr_press (Button &)
 {
 //	access_action("Mixer/select-none");
-	set_stripable_selection( _session->master_out() );
+	set_stripable_selection (master_out());
 	return on;
 }
 
diff --git a/libs/surfaces/us2400/surface.cc b/libs/surfaces/us2400/surface.cc
index 11acbb7be8..65f24bcc7c 100644
--- a/libs/surfaces/us2400/surface.cc
+++ b/libs/surfaces/us2400/surface.cc
@@ -371,8 +371,8 @@ Surface::setup_master ()
 {
 	boost::shared_ptr<Stripable> m;
 
-	if ((m = _mcp.get_session().monitor_out()) == 0) {
-		m = _mcp.get_session().master_out();
+	if ((m = _mcp.monitor_out()) == 0) {
+		m = _mcp.master_out();
 	}
 
 	if (!m) {
diff --git a/libs/surfaces/us2400/us2400_control_protocol.cc b/libs/surfaces/us2400/us2400_control_protocol.cc
index c35c824f18..27ca8176ff 100644
--- a/libs/surfaces/us2400/us2400_control_protocol.cc
+++ b/libs/surfaces/us2400/us2400_control_protocol.cc
@@ -1496,13 +1496,13 @@ US2400Protocol::display_view_mode ()
 void
 US2400Protocol::set_master_on_surface_strip (uint32_t surface, uint32_t strip_number)
 {
-	force_special_stripable_to_strip (_session->master_out(), surface, strip_number);
+	force_special_stripable_to_strip (master_out (), surface, strip_number);
 }
 
 void
 US2400Protocol::set_monitor_on_surface_strip (uint32_t surface, uint32_t strip_number)
 {
-	force_special_stripable_to_strip (_session->monitor_out(), surface, strip_number);
+	force_special_stripable_to_strip (monitor_out (), surface, strip_number);
 }
 
 void
@@ -1518,7 +1518,7 @@ US2400Protocol::force_special_stripable_to_strip (boost::shared_ptr<Stripable> r
 		if ((*s)->number() == surface) {
 			Strip* strip = (*s)->nth_strip (strip_number);
 			if (strip) {
-				strip->set_stripable (_session->master_out());
+				strip->set_stripable (master_out ());
 				strip->lock_controls ();
 			}
 		}