diff --git a/include/application.h b/include/application.h
index 4c1e030..5d690d1 100644
--- a/include/application.h
+++ b/include/application.h
@@ -25,6 +25,7 @@ private:
     std::array<std::shared_ptr<GUIState>, GUIState::Tag::AMOUNT> _states;
     std::vector<std::shared_ptr<GUIState>> _state_stack;
 
+
     sf::RenderWindow _game_window;
     std::shared_ptr<Game> _game;
 
diff --git a/include/tools/bpmcalculator.h b/include/tools/bpmcalculator.h
index d25d9e7..7e2325d 100644
--- a/include/tools/bpmcalculator.h
+++ b/include/tools/bpmcalculator.h
@@ -8,16 +8,33 @@ class BPMCalculator
 {
 public:
     explicit BPMCalculator(const std::shared_ptr<Music>& music);
+
     void setMusic(const std::shared_ptr<Music>& music);
     std::shared_ptr<Music> music() const;
 
     void start();
-
+    void stop();
     void click();
-    int getCurrentApproximation() const;
+    float fetchCurrentBPMApproximation();
+
+    microsec getStartingOffset() const;
+    void setStartingOffset(microsec offset);
+    void moveStartingOffsetBy(microsec shift);
+
+    microsec fetchTimeUntilNextBeat();
+    microsec fetchBeatInterval();
 
 private:
+    bool _need_recalculate;
+    bool _calculating;
+
     std::shared_ptr<Music> _music;
     std::vector<microsec> _deltas;
     microsec _previous_click_offset;
+    microsec _first_click_offset;
+
+    int _approximated_bpm;
+
+    inline float calculateBPM(microsec all_microseconds, std::size_t beats_amount) const;
+    inline void reset();
 };
diff --git a/src/application.cpp b/src/application.cpp
index 1dc4fd8..55ed761 100644
--- a/src/application.cpp
+++ b/src/application.cpp
@@ -26,12 +26,18 @@ Application::Application() :
     _game_window.setMouseCursorGrabbed(false);
     _game_window.setVerticalSyncEnabled(true);
 
-    MainMenu::Callbacks callbacks = {[&](){ pushState(GUIState::Tag::EDITOR); }};
+    MainMenu::Callbacks callbacks =
+    {
+        [&](){ pushState(GUIState::Tag::GAME); },
+        [&](){ pushState(GUIState::Tag::EDITOR); }
+    };
+
     Editor::Callbacks editor_callbacks = {[&](){ popState(); }};
 
     const auto main_menu = std::make_shared<MainMenu>(_game_window, std::move(callbacks), _font_holder);
     const auto game_state = std::make_shared<GameState>(_game_window, _game, GameState::Callbacks());
     const auto editor = std::make_shared<Editor>(_game_window, std::move(editor_callbacks), std::make_unique<MusicSFML>(), _font_holder);
+
     _states[GUIState::Tag::MAIN_MENU] = main_menu;
     _states[GUIState::Tag::GAME] = game_state;
     _states[GUIState::Tag::EDITOR] = editor;
diff --git a/src/gui/editor.cpp b/src/gui/editor.cpp
index 2698e03..a99704d 100644
--- a/src/gui/editor.cpp
+++ b/src/gui/editor.cpp
@@ -106,5 +106,6 @@ void Editor::enter()
 void Editor::leave()
 {
     _group.reset();
+    _bpm_calculator.reset();
 }
 
diff --git a/src/gui/mainmenu.cpp b/src/gui/mainmenu.cpp
index e393740..6724262 100644
--- a/src/gui/mainmenu.cpp
+++ b/src/gui/mainmenu.cpp
@@ -9,18 +9,23 @@ MainMenu::MainMenu(sf::RenderWindow& game_window, Callbacks&& callbacks, const F
     const float window_width = game_window.getSize().x;
     const float window_height = game_window.getSize().y;
 
-    std::shared_ptr<PushButton> button_start = std::make_shared<PushButton>("Start", font_holder.get(Fonts::Id::GUI), 48);
-    button_start->setRect(sf::FloatRect(window_width / 3., window_height / 7. * 2, window_width / 3., window_height / 7.));
+    auto button_start = std::make_shared<PushButton>("Start", font_holder.get(Fonts::Id::GUI), 48);
+    button_start->setRect(sf::FloatRect(window_width / 3., window_height / 7., window_width / 3., window_height / 7.));
     button_start->setCallback(callbacks.onAppendGameState);
 
-    std::shared_ptr<PushButton> button_exit = std::make_shared<PushButton>("Exit", font_holder.get(Fonts::Id::GUI), 48);
-    button_exit->setRect(sf::FloatRect(window_width / 3., window_height / 7. * 4, window_width / 3., window_height / 7.));
+    auto button_editor = std::make_shared<PushButton>("Editor", font_holder.get(Fonts::Id::GUI), 48);
+    button_editor->setRect(sf::FloatRect(window_width / 3., window_height / 7. * 3, window_width / 3., window_height / 7.));
+    button_editor->setCallback(callbacks.onAppendEditorState);
+
+    auto button_exit = std::make_shared<PushButton>("Exit", font_holder.get(Fonts::Id::GUI), 48);
+    button_exit->setRect(sf::FloatRect(window_width / 3., window_height / 7. * 5, window_width / 3., window_height / 7.));
     button_exit->setCallback([&]()
     {
         _game_window.close();
     });
 
     _buttons->addChild(button_start);
+    _buttons->addChild(button_editor);
     _buttons->addChild(button_exit);
 }
 
diff --git a/src/gui/mainmenu.h b/src/gui/mainmenu.h
index a2d4c78..f5fee9e 100644
--- a/src/gui/mainmenu.h
+++ b/src/gui/mainmenu.h
@@ -13,6 +13,7 @@ public:
     struct Callbacks
     {
         std::function<void(void)> onAppendGameState;
+        std::function<void(void)> onAppendEditorState;
     };
 
     explicit MainMenu(sf::RenderWindow& game_window, Callbacks&& callbacks, const FontHolder &font_holder);
diff --git a/src/gui/widgets/bpmcalculatorwidget.cpp b/src/gui/widgets/bpmcalculatorwidget.cpp
index 1894a34..a3585e3 100644
--- a/src/gui/widgets/bpmcalculatorwidget.cpp
+++ b/src/gui/widgets/bpmcalculatorwidget.cpp
@@ -34,10 +34,18 @@ void BPMCalculatorWidget::update(const sf::Time& dt)
 {
     Window::update(dt);
 
-    const auto approximation = _bpm_calculator->getCurrentApproximation();
+    const auto approximation = _bpm_calculator->fetchCurrentBPMApproximation();
     if (approximation != 0)
     {
         _bpm_value.setString(std::to_string(approximation));
+
+        const microsec until_beat = _bpm_calculator->fetchTimeUntilNextBeat();
+        const microsec beat_interval = _bpm_calculator->fetchBeatInterval();
+
+        const auto time_relation = beat_interval / until_beat;
+        const auto slider_path_left = Window::rect().width / time_relation;
+
+        _slider->setTickPosition(slider_path_left);
     }
 }
 
diff --git a/src/gui/widgets/bpmslider.cpp b/src/gui/widgets/bpmslider.cpp
index 4b81ffc..f459cb3 100644
--- a/src/gui/widgets/bpmslider.cpp
+++ b/src/gui/widgets/bpmslider.cpp
@@ -49,3 +49,17 @@ bool BPMSlider::isUnderMouse(int mouse_x, int mouse_y) const
     return mouse_x == mouse_y; // just to compile
 }
 
+sf::FloatRect BPMSlider::rect() const
+{
+    return _slider_background.getGlobalBounds();
+}
+
+sf::Vector2f BPMSlider::position() const
+{
+    return _slider_background.getPosition();
+}
+
+void BPMSlider::setTickPosition(float x_position)
+{
+    _slider_tick.setPosition(_slider_background.getPosition().x + x_position, _slider_tick.getPosition().y);
+}
diff --git a/src/gui/widgets/bpmslider.h b/src/gui/widgets/bpmslider.h
index be56969..facc018 100644
--- a/src/gui/widgets/bpmslider.h
+++ b/src/gui/widgets/bpmslider.h
@@ -13,11 +13,17 @@ public:
     virtual void input(const sf::Event& event) override;
     virtual void update(const sf::Time& dt) override;
     virtual void draw(sf::RenderTarget& target, sf::RenderStates states) const override;
-    virtual void setRect(const sf::FloatRect& rect) override;
-    virtual void setPosition(const sf::Vector2f& position) override;
     virtual void move(const sf::Vector2f& delta) override;
     virtual bool isUnderMouse(int mouse_x, int mouse_y) const override;
 
+    virtual void setRect(const sf::FloatRect& rect) override;
+    virtual sf::FloatRect rect() const override;
+
+    virtual void setPosition(const sf::Vector2f& position) override;
+    virtual sf::Vector2f position() const override;
+
+    void setTickPosition(float x_position);
+
 private:
     sf::RectangleShape _slider_background;
     sf::RectangleShape _slider_tick;
diff --git a/src/gui/widgets/button.cpp b/src/gui/widgets/button.cpp
index 371b2fa..742b6bb 100644
--- a/src/gui/widgets/button.cpp
+++ b/src/gui/widgets/button.cpp
@@ -54,3 +54,13 @@ void Button::setText(const std::string& text)
 {
     _button_text.setString(text);
 }
+
+sf::FloatRect Button::rect() const
+{
+    return _button_content.getGlobalBounds();
+}
+
+sf::Vector2f Button::position() const
+{
+    return _button_content.getPosition();
+}
diff --git a/src/gui/widgets/button.h b/src/gui/widgets/button.h
index cf121aa..5aeac8d 100644
--- a/src/gui/widgets/button.h
+++ b/src/gui/widgets/button.h
@@ -13,11 +13,14 @@ public:
     virtual void input(const sf::Event& event) override = 0;
     virtual void update(const sf::Time& dt) override final;
     virtual void draw(sf::RenderTarget& target, sf::RenderStates states) const override final;
-    virtual void setPosition(const sf::Vector2f& position) override final;
     virtual void move(const sf::Vector2f& delta) override final;
     virtual bool isUnderMouse(int mouse_x, int mouse_y) const override final;
 
     virtual void setRect(const sf::FloatRect& rect) override;
+    virtual sf::FloatRect rect() const override;
+
+    virtual void setPosition(const sf::Vector2f& position) override;
+    virtual sf::Vector2f position() const override;
 
     virtual void setText(const std::string& text);
 
diff --git a/src/gui/widgets/group.cpp b/src/gui/widgets/group.cpp
index 332dcf0..03d5944 100644
--- a/src/gui/widgets/group.cpp
+++ b/src/gui/widgets/group.cpp
@@ -38,3 +38,18 @@ bool Group::isUnderMouse(int mouse_x, int mouse_y) const
 {
    return _rect.contains(mouse_x, mouse_y);
 }
+
+sf::FloatRect Group::rect() const
+{
+    return _rect;
+}
+
+sf::Vector2f Group::position() const
+{
+    return sf::Vector2f
+    {
+        _rect.top,
+        _rect.left
+    };
+}
+
diff --git a/src/gui/widgets/group.h b/src/gui/widgets/group.h
index b3d9dc4..4f67bd1 100644
--- a/src/gui/widgets/group.h
+++ b/src/gui/widgets/group.h
@@ -8,11 +8,15 @@ public:
     virtual void input(const sf::Event& event) override;
     virtual void update(const sf::Time& dt) override;
     virtual void draw(sf::RenderTarget& target, sf::RenderStates states) const override;
-    virtual void setRect(const sf::FloatRect& rect) override;
-    virtual void setPosition(const sf::Vector2f& position) override;
     virtual void move(const sf::Vector2f& delta) override;
     virtual bool isUnderMouse(int mouse_x, int mouse_y) const override;
 
+    virtual void setRect(const sf::FloatRect& rect) override;
+    virtual sf::FloatRect rect() const override;
+
+    virtual void setPosition(const sf::Vector2f& position) override;
+    virtual sf::Vector2f position() const override;
+
 private:
     sf::FloatRect _rect;
 };
diff --git a/src/gui/widgets/menubar.cpp b/src/gui/widgets/menubar.cpp
index 965c9d3..fa14f56 100644
--- a/src/gui/widgets/menubar.cpp
+++ b/src/gui/widgets/menubar.cpp
@@ -113,3 +113,13 @@ void MenuBar::setVisibility(bool is_visible)
     for (auto& submenu : _submenus)
         submenu->setVisibility(false);
 }
+
+sf::FloatRect MenuBar::rect() const
+{
+    return _bar_rect.getGlobalBounds();
+}
+
+sf::Vector2f MenuBar::position() const
+{
+    return _bar_rect.getPosition();
+}
diff --git a/src/gui/widgets/menubar.h b/src/gui/widgets/menubar.h
index 0183a59..fea7be5 100644
--- a/src/gui/widgets/menubar.h
+++ b/src/gui/widgets/menubar.h
@@ -14,12 +14,16 @@ public:
     virtual void input(const sf::Event& event) override;
     virtual void update(const sf::Time& dt) override;
     virtual void draw(sf::RenderTarget& target, sf::RenderStates states) const override;
-    virtual void setRect(const sf::FloatRect& rect) override;
-    virtual void setPosition(const sf::Vector2f& position) override;
     virtual void move(const sf::Vector2f& delta) override;
     virtual bool isUnderMouse(int mouse_x, int mouse_y) const override;
     virtual void setVisibility(bool is_visible = true) override;
 
+    virtual void setRect(const sf::FloatRect& rect) override;
+    virtual sf::FloatRect rect() const override;
+
+    virtual void setPosition(const sf::Vector2f& position) override;
+    virtual sf::Vector2f position() const override;
+
     void addRootSubMenu(std::string name, const std::shared_ptr<MenuDrop>& submenu);
     void addDependentSubmenu(const std::shared_ptr<MenuDrop>& submenu);
 
diff --git a/src/gui/widgets/menudrop.cpp b/src/gui/widgets/menudrop.cpp
index 222c6e1..1eebfbc 100644
--- a/src/gui/widgets/menudrop.cpp
+++ b/src/gui/widgets/menudrop.cpp
@@ -147,3 +147,12 @@ bool MenuDrop::isLocked() const
     return _is_locked;
 }
 
+sf::FloatRect MenuDrop::rect() const
+{
+    return _content_rect.getGlobalBounds();
+}
+
+sf::Vector2f MenuDrop::position() const
+{
+    return _content_rect.getPosition();
+}
diff --git a/src/gui/widgets/menudrop.h b/src/gui/widgets/menudrop.h
index 0bbac32..59e7b04 100644
--- a/src/gui/widgets/menudrop.h
+++ b/src/gui/widgets/menudrop.h
@@ -13,12 +13,16 @@ public:
     virtual void input(const sf::Event& event) override;
     virtual void update(const sf::Time& dt) override;
     virtual void draw(sf::RenderTarget& target, sf::RenderStates states) const override;
-    virtual void setRect(const sf::FloatRect& rect) override;
-    virtual void setPosition(const sf::Vector2f& position) override;
     virtual void move(const sf::Vector2f& delta) override;
     virtual bool isUnderMouse(int mouse_x, int mouse_y) const override;
     virtual void setVisibility(bool is_visible = true) override;
 
+    virtual void setRect(const sf::FloatRect& rect) override;
+    virtual sf::FloatRect rect() const override;
+
+    virtual void setPosition(const sf::Vector2f& position) override;
+    virtual sf::Vector2f position() const override;
+
     void addPushButton(const std::shared_ptr<PushButton>& button);
     void addCascadeButton(const std::shared_ptr<CascadeMenuButton>& button);
     void addSeparator();
diff --git a/src/gui/widgets/menuseparator.cpp b/src/gui/widgets/menuseparator.cpp
index 249b537..abe0fb5 100644
--- a/src/gui/widgets/menuseparator.cpp
+++ b/src/gui/widgets/menuseparator.cpp
@@ -37,3 +37,12 @@ bool MenuSeparator::isUnderMouse(int mouse_x, int mouse_y) const
     return _is_visible && _rect.contains(mouse_x, mouse_y);
 }
 
+sf::FloatRect MenuSeparator::rect() const
+{
+    return {};
+}
+
+sf::Vector2f MenuSeparator::position() const
+{
+    return {};
+}
diff --git a/src/gui/widgets/menuseparator.h b/src/gui/widgets/menuseparator.h
index 7456276..2412355 100644
--- a/src/gui/widgets/menuseparator.h
+++ b/src/gui/widgets/menuseparator.h
@@ -10,11 +10,15 @@ public:
     virtual void input(const sf::Event& event) override;
     virtual void update(const sf::Time& dt) override;
     virtual void draw(sf::RenderTarget& target, sf::RenderStates states) const override;
-    virtual void setRect(const sf::FloatRect& rect) override;
-    virtual void setPosition(const sf::Vector2f& position) override;
     virtual void move(const sf::Vector2f& delta) override;
     virtual bool isUnderMouse(int mouse_x, int mouse_y) const override;
 
+    virtual void setRect(const sf::FloatRect& rect) override;
+    virtual sf::FloatRect rect() const override;
+
+    virtual void setPosition(const sf::Vector2f& position) override;
+    virtual sf::Vector2f position() const override;
+
 private:
     sf::VertexArray _line;
     sf::FloatRect _rect;
diff --git a/src/gui/widgets/widget.h b/src/gui/widgets/widget.h
index 9091d4d..ac25b3b 100644
--- a/src/gui/widgets/widget.h
+++ b/src/gui/widgets/widget.h
@@ -14,11 +14,15 @@ public:
     virtual void input(const sf::Event& event) = 0;
     virtual void update(const sf::Time& dt) = 0;
     virtual void draw(sf::RenderTarget& target, sf::RenderStates states) const = 0;
-    virtual void setRect(const sf::FloatRect& rect) = 0;
-    virtual void setPosition(const sf::Vector2f& position) = 0;
     virtual void move(const sf::Vector2f& delta) = 0;
     virtual bool isUnderMouse(int mouse_x, int mouse_y) const = 0;
 
+    virtual void setRect(const sf::FloatRect& rect) = 0;
+    virtual sf::FloatRect rect() const = 0;
+
+    virtual void setPosition(const sf::Vector2f& position) = 0;
+    virtual sf::Vector2f position() const = 0;
+
     virtual void setVisibility(bool is_visible = true);
     bool isVisible() const;
 
diff --git a/src/gui/widgets/window.cpp b/src/gui/widgets/window.cpp
index c918f9a..4155fce 100644
--- a/src/gui/widgets/window.cpp
+++ b/src/gui/widgets/window.cpp
@@ -108,3 +108,12 @@ void Window::addBarButton(const std::string &text, std::function<void(void)> cal
     addChild(b);
 }
 
+sf::FloatRect Window::rect() const
+{
+    return _window_content.getGlobalBounds();
+}
+
+sf::Vector2f Window::position() const
+{
+    return _window_content.getPosition();
+}
diff --git a/src/gui/widgets/window.h b/src/gui/widgets/window.h
index ee52d40..0ff69ab 100644
--- a/src/gui/widgets/window.h
+++ b/src/gui/widgets/window.h
@@ -13,11 +13,15 @@ public:
     virtual void input(const sf::Event& event) override;
     virtual void update(const sf::Time& dt) override;
     virtual void draw(sf::RenderTarget& target, sf::RenderStates states) const override;
-    virtual void setRect(const sf::FloatRect& rect) override;
-    virtual void setPosition(const sf::Vector2f& position) override;
     virtual void move(const sf::Vector2f& delta) override;
     virtual bool isUnderMouse(int mouse_x, int mouse_y) const override final;
 
+    virtual void setRect(const sf::FloatRect& rect) override;
+    virtual sf::FloatRect rect() const override;
+
+    virtual void setPosition(const sf::Vector2f& position) override;
+    virtual sf::Vector2f position() const override;
+
     void addBarButton(const std::string& text, std::function<void(void)> callback);
 
 protected:
diff --git a/src/tools/bpmcalculator.cpp b/src/tools/bpmcalculator.cpp
index 118850b..fde8b9d 100644
--- a/src/tools/bpmcalculator.cpp
+++ b/src/tools/bpmcalculator.cpp
@@ -3,18 +3,27 @@
 #include <numeric>
 #include <iostream>
 
-constexpr microsec MICROSECONDS_IN_MINUTE = 60000000;
+constexpr float MICROSECONDS_IN_MINUTE_f = 60000000.;
 
 BPMCalculator::BPMCalculator(const std::shared_ptr<Music>& music) :
-    _music(music),
-    _previous_click_offset(0)
-{}
+    _music(music)
+{
+    reset();
+}
+
+void BPMCalculator::reset()
+{
+    _calculating = false;
+    _deltas.clear();
+    _previous_click_offset = 0;
+    _approximated_bpm = 0;
+    _need_recalculate = true;
+}
 
 void BPMCalculator::setMusic(const std::shared_ptr<Music>& music)
 {
-    _deltas.clear();
-    _previous_click_offset = 0;
     _music = music;
+    reset();
 }
 
 std::shared_ptr<Music> BPMCalculator::music() const
@@ -24,15 +33,23 @@ std::shared_ptr<Music> BPMCalculator::music() const
 
 void BPMCalculator::start()
 {
-    _deltas.clear();
-    _previous_click_offset = 0;
+    reset();
+
+    _calculating = true;
+}
+
+void BPMCalculator::stop()
+{
+    _calculating = false;
 }
 
 void BPMCalculator::click()
 {
-    const microsec click_offset = _music->fetchOffset();
+    if (!_calculating)
+        return;
 
-    std::cout << click_offset << "\n\n\n\n";
+    const microsec click_offset = _music->fetchOffset();
+    _need_recalculate = true;
 
     if (_previous_click_offset == 0)
     {
@@ -46,14 +63,57 @@ void BPMCalculator::click()
     _previous_click_offset = click_offset;
 }
 
-int BPMCalculator::getCurrentApproximation() const
+float BPMCalculator::fetchCurrentBPMApproximation()
 {
+    if (!_need_recalculate)
+        return _approximated_bpm;
+
+    _need_recalculate = false;
+
     const microsec sum = std::accumulate(_deltas.begin(), _deltas.end(), 0);
+    bool hasEnoughDeltas = _deltas.size() >= 8;
 
-    std::cout << "S: " << sum << "  _deltas.size(): " << _deltas.size();
-    std::cout << "\n    " << (static_cast<float>(sum) / static_cast<float>(_deltas.size())) << '\n';
+    _approximated_bpm = (!hasEnoughDeltas)
+                      ?  0.
+                      :  calculateBPM(sum, _deltas.size());
 
-    return (sum == 0 || _deltas.size() < 8)
-         ?  0.
-         :  static_cast<int>(static_cast<float>(MICROSECONDS_IN_MINUTE) / (static_cast<float>(sum) / static_cast<float>(_deltas.size())));
+    return _approximated_bpm;
+}
+
+float BPMCalculator::calculateBPM(microsec all_microseconds, std::size_t beats_amount) const
+{
+    if (beats_amount == 0)
+        return 0;
+
+    float relation = static_cast<float>(all_microseconds)
+                   / static_cast<float>(beats_amount);
+
+    return static_cast<float>(1. / relation);
+}
+
+microsec BPMCalculator::getStartingOffset() const
+{
+    return _first_click_offset;
+}
+
+void BPMCalculator::setStartingOffset(microsec offset)
+{
+    _first_click_offset = offset;
+}
+
+void BPMCalculator::moveStartingOffsetBy(microsec shift)
+{
+    _first_click_offset += shift;
+}
+
+microsec BPMCalculator::fetchTimeUntilNextBeat()
+{
+    const microsec actual_offset = _music->fetchOffset() - _first_click_offset;
+
+    return fetchBeatInterval() % actual_offset;
+}
+
+microsec BPMCalculator::fetchBeatInterval()
+{
+    return static_cast<microsec>(1. / fetchCurrentBPMApproximation());
 }