diff --git a/include/tools/bpmcalculator.h b/include/tools/bpmcalculator.h
index 72f5ba1..d25d9e7 100644
--- a/include/tools/bpmcalculator.h
+++ b/include/tools/bpmcalculator.h
@@ -9,6 +9,7 @@ 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();
 
diff --git a/src/gui/editor.cpp b/src/gui/editor.cpp
index 13200b0..2698e03 100644
--- a/src/gui/editor.cpp
+++ b/src/gui/editor.cpp
@@ -33,11 +33,16 @@ void Editor::draw() const
 void Editor::enter()
 {
     auto& group = _group;
+    auto& music = _music;
+    _music->openFromFile("40mp.ogg");
+    _music->setVolume(5);
 
     _bpm_calculator = std::make_shared<BPMCalculator>(_music);
     std::shared_ptr<BPMCalculatorWidget> bpm_widget = std::make_shared<BPMCalculatorWidget>(_bpm_calculator, _font);
-    const auto bpm_widget_callback = [&group, bpm_widget=bpm_widget]()
+    bpm_widget->init();
+    const auto bpm_widget_callback = [&group, bpm_widget=bpm_widget, &music]()
     {
+        music->stop();
         bpm_widget->setVisibility(false);
         group->unblock();
     };
@@ -91,9 +96,6 @@ void Editor::enter()
     test_menu_2->addCascadeButton(test_cascade_button_2);
     test_cascade_button_2->resetRect();
 
-    _music->openFromFile("Uta-test.flac");
-    _music->setVolume(5);
-
     menu_bar->setVisibility(true);
 
     _group = std::make_shared<Group>();
diff --git a/src/gui/widgets/bpmcalculatorwidget.cpp b/src/gui/widgets/bpmcalculatorwidget.cpp
index 8b226c7..1894a34 100644
--- a/src/gui/widgets/bpmcalculatorwidget.cpp
+++ b/src/gui/widgets/bpmcalculatorwidget.cpp
@@ -6,6 +6,10 @@ BPMCalculatorWidget::BPMCalculatorWidget(const std::shared_ptr<BPMCalculator>& b
     _bpm_calculator(bpm_calculator),
     _slider(std::make_shared<BPMSlider>())
 {
+    _bpm_value.setFont(*_font);
+    _bpm_value.setCharacterSize(40);
+    _bpm_value.setFillColor(sf::Color::Black);
+    _bpm_value.setString("--");
 }
 
 void BPMCalculatorWidget::input(const sf::Event& event)
@@ -29,6 +33,12 @@ void BPMCalculatorWidget::input(const sf::Event& event)
 void BPMCalculatorWidget::update(const sf::Time& dt)
 {
     Window::update(dt);
+
+    const auto approximation = _bpm_calculator->getCurrentApproximation();
+    if (approximation != 0)
+    {
+        _bpm_value.setString(std::to_string(approximation));
+    }
 }
 
 void BPMCalculatorWidget::draw(sf::RenderTarget& target, sf::RenderStates states) const
@@ -36,7 +46,11 @@ void BPMCalculatorWidget::draw(sf::RenderTarget& target, sf::RenderStates states
     Window::draw(target, states);
 
     if (_is_visible)
+    {
         _slider->draw(target, states);
+        _button_start->draw(target, states);
+        target.draw(_bpm_value, states);
+    }
 }
 
 void BPMCalculatorWidget::setRect(const sf::FloatRect& rect)
@@ -45,16 +59,38 @@ void BPMCalculatorWidget::setRect(const sf::FloatRect& rect)
     _slider->setRect(sf::FloatRect{0, 0, rect.width / 8 * 6, 100});
     _slider->setPosition({_window_content.getGlobalBounds().left + rect.width / 8,
                           _window_content.getGlobalBounds().top + rect.height / 8 * 3});
+
+    _button_start->setRect(sf::FloatRect{0, 0, rect.width / 10 * 3, 30});
+    _button_start->setPosition({_window_content.getGlobalBounds().left + rect.width / 7,
+                                _window_content.getGlobalBounds().top + _window_content.getGlobalBounds().height - 40});
+
+    _bpm_value.setPosition({_window_content.getGlobalBounds().left + rect.width / 8,
+                            _window_content.getGlobalBounds().top + rect.height / 8 });
 }
 
 void BPMCalculatorWidget::move(const sf::Vector2f &delta)
 {
     Window::move(delta);
     _slider->move(delta);
+    _bpm_value.move(delta);
 }
 
 void BPMCalculatorWidget::setPosition(const sf::Vector2f &position)
 {
     Window::setPosition(position);
-    _slider->setPosition(position);
+}
+
+void BPMCalculatorWidget::init()
+{
+    auto& bpm_calculator = _bpm_calculator;
+
+    _button_start = std::make_shared<PushButton>("Start", _font);
+    _button_start->setCallback([bpm_calculator, button_start=_button_start]()
+    {
+        bpm_calculator->music()->play();
+        bpm_calculator->start();
+        button_start->setVisibility(false);
+    });
+
+    addChild(_button_start);
 }
diff --git a/src/gui/widgets/bpmcalculatorwidget.h b/src/gui/widgets/bpmcalculatorwidget.h
index 9e44d43..a3aa616 100644
--- a/src/gui/widgets/bpmcalculatorwidget.h
+++ b/src/gui/widgets/bpmcalculatorwidget.h
@@ -21,8 +21,13 @@ public:
     virtual void setPosition(const sf::Vector2f& position) override;
     virtual void move(const sf::Vector2f& delta) override;
 
+    void init();
+
 private:
+    std::shared_ptr<PushButton> _button_start;
     std::shared_ptr<BPMCalculator> _bpm_calculator;
     std::shared_ptr<BPMSlider> _slider;
+
+    sf::Text _bpm_value;
 };
 
diff --git a/src/gui/widgets/button.cpp b/src/gui/widgets/button.cpp
index cc4e83f..371b2fa 100644
--- a/src/gui/widgets/button.cpp
+++ b/src/gui/widgets/button.cpp
@@ -35,6 +35,7 @@ void Button::setRect(const sf::FloatRect& rect)
 void Button::setPosition(const sf::Vector2f &position)
 {
     _button_content.setPosition(position);
+    _button_text.move(position.x + 5, position.y + 5);
 }
 
 void Button::move(const sf::Vector2f &delta)
diff --git a/src/tools/bpmcalculator.cpp b/src/tools/bpmcalculator.cpp
index a1ce4ac..118850b 100644
--- a/src/tools/bpmcalculator.cpp
+++ b/src/tools/bpmcalculator.cpp
@@ -17,10 +17,15 @@ void BPMCalculator::setMusic(const std::shared_ptr<Music>& music)
     _music = music;
 }
 
+std::shared_ptr<Music> BPMCalculator::music() const
+{
+    return _music;
+}
+
 void BPMCalculator::start()
 {
     _deltas.clear();
-    _previous_click_offset = _music->fetchOffset();
+    _previous_click_offset = 0;
 }
 
 void BPMCalculator::click()
@@ -29,7 +34,7 @@ void BPMCalculator::click()
 
     std::cout << click_offset << "\n\n\n\n";
 
-    if (_deltas.empty())
+    if (_previous_click_offset == 0)
     {
         _previous_click_offset = click_offset;
         return;
@@ -48,7 +53,7 @@ int BPMCalculator::getCurrentApproximation() const
     std::cout << "S: " << sum << "  _deltas.size(): " << _deltas.size();
     std::cout << "\n    " << (static_cast<float>(sum) / static_cast<float>(_deltas.size())) << '\n';
 
-    return (sum == 0)
+    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())));
 }