diff --git a/libs/ardour/ardour/session_playlists.h b/libs/ardour/ardour/session_playlists.h
new file mode 100644
index 0000000000..1fca497143
--- /dev/null
+++ b/libs/ardour/ardour/session_playlists.h
@@ -0,0 +1,55 @@
+#ifndef __ardour_session_playlists_h__
+#define __ardour_session_playlists_h__
+
+#include <set>
+#include <vector>
+#include <string>
+#include <glibmm/thread.h>
+#include <boost/shared_ptr.hpp>
+#include <sigc++/trackable.h>
+
+class XMLNode;
+
+namespace ARDOUR {
+
+class Playlist;
+class Region;
+class Source;
+class Session;
+	
+class SessionPlaylists : public sigc::trackable
+{
+public:
+	~SessionPlaylists ();
+	
+	boost::shared_ptr<Playlist> by_name (std::string name);
+	uint32_t source_use_count (boost::shared_ptr<const Source> src) const;
+	template<class T> void foreach (T *obj, void (T::*func)(boost::shared_ptr<Playlist>));
+	void get (std::vector<boost::shared_ptr<Playlist> >&);
+	void unassigned (std::list<boost::shared_ptr<Playlist> > & list);
+
+private:
+	friend class Session;
+	
+	bool add (boost::shared_ptr<Playlist>);
+	void remove (boost::shared_ptr<Playlist>);
+	void track (bool, boost::weak_ptr<Playlist>);
+	
+	uint32_t n_playlists() const;
+	void find_equivalent_playlist_regions (boost::shared_ptr<Region>, std::vector<boost::shared_ptr<Region> >& result);
+	void update_after_tempo_map_change ();
+	void add_state (XMLNode *, bool);
+	bool maybe_delete_unused (sigc::signal<int, boost::shared_ptr<Playlist> >);
+	int load (Session &, const XMLNode&);
+	int load_unused (Session &, const XMLNode&);
+	boost::shared_ptr<Playlist> XMLPlaylistFactory (Session &, const XMLNode&);
+
+	mutable Glib::Mutex lock;
+	typedef std::set<boost::shared_ptr<Playlist> > List;
+	List playlists;
+	List unused_playlists;
+};
+
+}
+
+#endif
diff --git a/libs/ardour/session_playlists.cc b/libs/ardour/session_playlists.cc
new file mode 100644
index 0000000000..362d812c36
--- /dev/null
+++ b/libs/ardour/session_playlists.cc
@@ -0,0 +1,336 @@
+#include "pbd/xml++.h"
+#include "pbd/compose.h"
+#include "ardour/debug.h"
+#include "ardour/session_playlists.h"
+#include "ardour/playlist.h"
+#include "ardour/region.h"
+#include "ardour/playlist_factory.h"
+#include "ardour/session.h"
+#include "i18n.h"
+
+using namespace std;
+using namespace PBD;
+using namespace ARDOUR;
+
+SessionPlaylists::~SessionPlaylists ()
+{
+	DEBUG_TRACE (DEBUG::Destruction, "delete playlists\n");
+	
+	for (List::iterator i = playlists.begin(); i != playlists.end(); ) {
+		SessionPlaylists::List::iterator tmp;
+
+		tmp = i;
+		++tmp;
+
+		DEBUG_TRACE(DEBUG::Destruction, string_compose ("Dropping for used playlist %1 ; pre-ref = %2\n", (*i)->name(), (*i).use_count()));
+		(*i)->drop_references ();
+
+		i = tmp;
+	}
+
+	DEBUG_TRACE (DEBUG::Destruction, "delete unused playlists\n");
+	for (List::iterator i = unused_playlists.begin(); i != unused_playlists.end(); ) {
+		List::iterator tmp;
+
+		tmp = i;
+		++tmp;
+
+		DEBUG_TRACE(DEBUG::Destruction, string_compose ("Dropping for unused playlist %1 ; pre-ref = %2\n", (*i)->name(), (*i).use_count()));
+		(*i)->drop_references ();
+
+		i = tmp;
+	}
+
+	playlists.clear ();
+	unused_playlists.clear ();
+}
+
+bool
+SessionPlaylists::add (boost::shared_ptr<Playlist> playlist)
+{
+	Glib::Mutex::Lock lm (lock);
+
+	bool const existing = find (playlists.begin(), playlists.end(), playlist) != playlists.end();
+
+	if (!existing) {
+		playlists.insert (playlists.begin(), playlist);
+		playlist->InUse.connect (sigc::bind (mem_fun (*this, &SessionPlaylists::track), boost::weak_ptr<Playlist>(playlist)));
+	}
+
+	return existing;
+}
+
+void
+SessionPlaylists::remove (boost::shared_ptr<Playlist> playlist)
+{
+	Glib::Mutex::Lock lm (lock);
+
+	List::iterator i;
+
+	i = find (playlists.begin(), playlists.end(), playlist);
+	if (i != playlists.end()) {
+		playlists.erase (i);
+	}
+
+	i = find (unused_playlists.begin(), unused_playlists.end(), playlist);
+	if (i != unused_playlists.end()) {
+		unused_playlists.erase (i);
+	}
+}
+	
+
+void
+SessionPlaylists::track (bool inuse, boost::weak_ptr<Playlist> wpl)
+{
+	boost::shared_ptr<Playlist> pl(wpl.lock());
+
+	if (!pl) {
+		return;
+	}
+
+	List::iterator x;
+
+	if (pl->hidden()) {
+		/* its not supposed to be visible */
+		return;
+	}
+
+	{
+		Glib::Mutex::Lock lm (lock);
+
+		if (!inuse) {
+
+			unused_playlists.insert (pl);
+
+			if ((x = playlists.find (pl)) != playlists.end()) {
+				playlists.erase (x);
+			}
+
+
+		} else {
+
+			playlists.insert (pl);
+
+			if ((x = unused_playlists.find (pl)) != unused_playlists.end()) {
+				unused_playlists.erase (x);
+			}
+		}
+	}
+}
+
+uint32_t
+SessionPlaylists::n_playlists () const
+{
+	Glib::Mutex::Lock lm (lock);
+	return playlists.size();
+}
+
+boost::shared_ptr<Playlist>
+SessionPlaylists::by_name (string name)
+{
+	Glib::Mutex::Lock lm (lock);
+
+	for (List::iterator i = playlists.begin(); i != playlists.end(); ++i) {
+		if ((*i)->name() == name) {
+			return* i;
+		}
+	}
+	
+	for (List::iterator i = unused_playlists.begin(); i != unused_playlists.end(); ++i) {
+		if ((*i)->name() == name) {
+			return* i;
+		}
+	}
+
+	return boost::shared_ptr<Playlist>();
+}
+
+void
+SessionPlaylists::unassigned (std::list<boost::shared_ptr<Playlist> > & list)
+{
+	Glib::Mutex::Lock lm (lock);
+
+	for (List::iterator i = playlists.begin(); i != playlists.end(); ++i) {
+		if (!(*i)->get_orig_diskstream_id().to_s().compare ("0")) {
+			list.push_back (*i);
+		}
+	}
+	
+	for (List::iterator i = unused_playlists.begin(); i != unused_playlists.end(); ++i) {
+		if (!(*i)->get_orig_diskstream_id().to_s().compare ("0")) {
+			list.push_back (*i);
+		}
+	}
+}
+
+void
+SessionPlaylists::get (vector<boost::shared_ptr<Playlist> >& s)
+{
+	Glib::Mutex::Lock lm (lock);
+
+	for (List::iterator i = playlists.begin(); i != playlists.end(); ++i) {
+		s.push_back (*i);
+	}
+	
+	for (List::iterator i = unused_playlists.begin(); i != unused_playlists.end(); ++i) {
+		s.push_back (*i);
+	}
+}
+
+void
+SessionPlaylists::find_equivalent_playlist_regions (boost::shared_ptr<Region> region, vector<boost::shared_ptr<Region> >& result)
+{
+	for (List::iterator i = playlists.begin(); i != playlists.end(); ++i)
+		(*i)->get_region_list_equivalent_regions (region, result);
+}
+
+/** Return the number of playlists (not regions) that contain @a src */
+uint32_t
+SessionPlaylists::source_use_count (boost::shared_ptr<const Source> src) const
+{
+	uint32_t count = 0;
+	for (List::const_iterator p = playlists.begin(); p != playlists.end(); ++p) {
+		for (Playlist::RegionList::const_iterator r = (*p)->region_list().begin();
+				r != (*p)->region_list().end(); ++r) {
+			if ((*r)->uses_source(src)) {
+				++count;
+				break;
+			}
+		}
+	}
+	return count;
+}
+
+
+void
+SessionPlaylists::update_after_tempo_map_change ()
+{
+	for (List::iterator i = playlists.begin(); i != playlists.end(); ++i) {
+		(*i)->update_after_tempo_map_change ();
+	}
+
+	for (List::iterator i = unused_playlists.begin(); i != unused_playlists.end(); ++i) {
+		(*i)->update_after_tempo_map_change ();
+	}
+}
+
+void
+SessionPlaylists::add_state (XMLNode* node, bool full_state)
+{
+	XMLNode* child = node->add_child ("Playlists");
+	for (List::iterator i = playlists.begin(); i != playlists.end(); ++i) {
+		if (!(*i)->hidden()) {
+			if (!(*i)->empty()) {
+				if (full_state) {
+					child->add_child_nocopy ((*i)->get_state());
+				} else {
+					child->add_child_nocopy ((*i)->get_template());
+				}
+			}
+		}
+	}
+
+	child = node->add_child ("UnusedPlaylists");
+	for (List::iterator i = unused_playlists.begin(); i != unused_playlists.end(); ++i) {
+		if (!(*i)->hidden()) {
+			if (!(*i)->empty()) {
+				if (full_state) {
+					child->add_child_nocopy ((*i)->get_state());
+				} else {
+					child->add_child_nocopy ((*i)->get_template());
+				}
+			}
+		}
+	}
+}
+
+/** @return true for `stop cleanup', otherwise false */
+bool
+SessionPlaylists::maybe_delete_unused (sigc::signal<int, boost::shared_ptr<Playlist> > ask)
+{
+	vector<boost::shared_ptr<Playlist> > playlists_tbd;
+
+	for (List::iterator x = unused_playlists.begin(); x != unused_playlists.end(); ++x) {
+
+		int status = ask (*x);
+
+		switch (status) {
+		case -1:
+			return true;
+
+		case 0:
+			playlists_tbd.push_back (*x);
+			break;
+
+		default:
+			/* leave it alone */
+			break;
+		}
+	}
+
+	/* now delete any that were marked for deletion */
+
+	for (vector<boost::shared_ptr<Playlist> >::iterator x = playlists_tbd.begin(); x != playlists_tbd.end(); ++x) {
+		(*x)->drop_references ();
+	}
+
+	playlists_tbd.clear ();
+
+	return false;
+}
+
+int
+SessionPlaylists::load (Session& session, const XMLNode& node)
+{
+	XMLNodeList nlist;
+	XMLNodeConstIterator niter;
+	boost::shared_ptr<Playlist> playlist;
+
+	nlist = node.children();
+
+	for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
+
+		if ((playlist = XMLPlaylistFactory (session, **niter)) == 0) {
+			error << _("Session: cannot create Playlist from XML description.") << endmsg;
+		}
+	}
+
+	return 0;
+}
+
+int
+SessionPlaylists::load_unused (Session& session, const XMLNode& node)
+{
+	XMLNodeList nlist;
+	XMLNodeConstIterator niter;
+	boost::shared_ptr<Playlist> playlist;
+
+	nlist = node.children();
+
+	for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
+
+		if ((playlist = XMLPlaylistFactory (session, **niter)) == 0) {
+			error << _("Session: cannot create Playlist from XML description.") << endmsg;
+			continue;
+		}
+
+		// now manually untrack it
+
+		track (false, boost::weak_ptr<Playlist> (playlist));
+	}
+
+	return 0;
+}
+
+boost::shared_ptr<Playlist>
+SessionPlaylists::XMLPlaylistFactory (Session& session, const XMLNode& node)
+{
+	try {
+		return PlaylistFactory::create (session, node);
+	}
+
+	catch (failed_constructor& err) {
+		return boost::shared_ptr<Playlist>();
+	}
+}
+