diff --git a/LenaPi/LenaPi.pro b/LenaPi/LenaPi.pro
index ab0a5a5..a043211 100644
--- a/LenaPi/LenaPi.pro
+++ b/LenaPi/LenaPi.pro
@@ -6,7 +6,10 @@ CONFIG += c++11
 SOURCES += main.cpp \
     models/NavigationListModel.cpp \
     models/NavigationItemModel.cpp \
-    controllers/NavigationController.cpp
+    controllers/NavigationController.cpp \
+    models/UiStateModel.cpp \
+    controllers/MusicController.cpp \
+    models/MusicModel.cpp
 
 RESOURCES += qml.qrc \
     lenapi.qrc
@@ -36,4 +39,7 @@ else: unix:!android: target.path = /opt/$${TARGET}/bin
 HEADERS += \
     models/NavigationListModel.h \
     models/NavigationItemModel.h \
-    controllers/NavigationController.h
+    controllers/NavigationController.h \
+    models/UiStateModel.h \
+    controllers/MusicController.h \
+    models/MusicModel.h
diff --git a/LenaPi/MusicPlayer.qml b/LenaPi/MusicPlayer.qml
index 04c4a72..c6c5ddb 100644
--- a/LenaPi/MusicPlayer.qml
+++ b/LenaPi/MusicPlayer.qml
@@ -7,7 +7,7 @@ Item{
         id: backgroundImage
 
         anchors.fill: parent
-        source: "file:///home/ar/source/testLenaPi/benjamin/image.jpg"
+        source: musicModel.pCurrentItem.pImageSource
         fillMode: Image.PreserveAspectCrop
         verticalAlignment: Image.AlignTop
     }
@@ -16,6 +16,9 @@ Item{
         anchors.left: parent.left
         anchors.top: parent.top
         anchors.margins: 20
+        onClicked: {
+            musicModel.navigateBack();
+        }
     }
 
     Rectangle {
@@ -34,6 +37,7 @@ Item{
             imageSource: "qrc:/icon_play"
 
             onClicked:{
+                musicModel.playPause();
                 if(imageSource == "qrc:/icon_play")
                     imageSource = "qrc:/icon_pause"
                 else
diff --git a/LenaPi/controllers/MusicController.cpp b/LenaPi/controllers/MusicController.cpp
new file mode 100644
index 0000000..1a545b6
--- /dev/null
+++ b/LenaPi/controllers/MusicController.cpp
@@ -0,0 +1,26 @@
+#include "MusicController.h"
+
+#include <models/MusicModel.h>
+
+MusicController::MusicController(QObject *parent) : QObject(parent),
+    mModel(new MusicModel(this))
+{
+    connect(mModel, &MusicModel::navigateTo, this, &MusicController::navigateTo);
+}
+
+void MusicController::initPlayer(NavigationItemModel *item)
+{
+    mModel->init(item);
+}
+
+void MusicController::setContext(QQmlContext *context)
+{
+    mContext = context;
+    setContextProperties();
+}
+
+void MusicController::setContextProperties()
+{
+    if(!mContext) return;
+    mContext->setContextProperty("musicModel", mModel);
+}
diff --git a/LenaPi/controllers/MusicController.h b/LenaPi/controllers/MusicController.h
new file mode 100644
index 0000000..7e456b0
--- /dev/null
+++ b/LenaPi/controllers/MusicController.h
@@ -0,0 +1,32 @@
+#ifndef MUSICCONTROLLER_H
+#define MUSICCONTROLLER_H
+
+#include <QObject>
+#include <QQmlContext>
+#include <models/NavigationItemModel.h>
+
+class MusicModel;
+
+class MusicController : public QObject
+{
+    Q_OBJECT
+
+signals:
+    void navigateTo(NavigationItemModel* item);
+
+public:
+    MusicController(QObject *parent = Q_NULLPTR);
+
+    void initPlayer(NavigationItemModel* item);
+
+    void setContext(QQmlContext* context);
+
+private:
+    void setContextProperties();
+
+    QQmlContext* mContext;
+
+    MusicModel* mModel;
+};
+
+#endif // MUSICCONTROLLER_H
diff --git a/LenaPi/controllers/NavigationController.cpp b/LenaPi/controllers/NavigationController.cpp
index 0a4b875..66064f2 100644
--- a/LenaPi/controllers/NavigationController.cpp
+++ b/LenaPi/controllers/NavigationController.cpp
@@ -3,15 +3,21 @@
 #include <QDir>
 #include <QDebug>
 
-#include "../models/NavigationItemModel.h"
-#include "../models/NavigationListModel.h"
+#include <models/NavigationItemModel.h>
+#include <models/NavigationListModel.h>
+#include <models/UiStateModel.h>
+#include <controllers/MusicController.h>
 
-///@todo impelement reaction to item's clicked signal; implement back navigation
 NavigationController::NavigationController(QObject *parent) : QObject(parent),
     mRootItem(new NavigationItemModel(this)),
-    mNavList(new NavigationListModel(this))
+    mNavList(new NavigationListModel(this)),
+    mUiState(new UiStateModel(this)),
+    mMusicController(new MusicController(this))
 {
-
+    connect(mMusicController, &MusicController::navigateTo, [this](NavigationItemModel* item) {
+        mUiState->showNavigation();
+        mNavList->navigateTo(item);
+    });
 }
 
 void NavigationController::init(const QString &rootPath)
@@ -29,11 +35,14 @@ void NavigationController::setContext(QQmlContext *context)
 {
     mContext = context;
     setContextProperties();
+    mMusicController->setContext(mContext);
 }
 
 void NavigationController::setContextProperties()
 {
+    if(!mContext) return;
     mContext->setContextProperty("navigationList", mNavList);
+    mContext->setContextProperty("uiStateModel", mUiState);
 }
 
 void NavigationController::add(const QString &path, NavigationItemModel *parentItem)
@@ -63,5 +72,8 @@ void NavigationController::onNavigationRequest()
 
     if(item->hasChildren())
         mNavList->setModelItems(item->getChildren());
-    ///@todo else {mMusicController->initPlayer(item); mUiStateModel->showMusicPlayer();}
+    else {
+        mMusicController->initPlayer(item);
+        mUiState->showMusicPlayer();
+    }
 }
diff --git a/LenaPi/controllers/NavigationController.h b/LenaPi/controllers/NavigationController.h
index 2576ba1..eb7ead0 100644
--- a/LenaPi/controllers/NavigationController.h
+++ b/LenaPi/controllers/NavigationController.h
@@ -6,6 +6,8 @@
 
 class NavigationItemModel;
 class NavigationListModel;
+class UiStateModel;
+class MusicController;
 
 class NavigationController : public QObject
 {
@@ -23,6 +25,10 @@ private:
 
     NavigationItemModel* mRootItem;
     NavigationListModel* mNavList;
+
+    UiStateModel* mUiState;
+    MusicController* mMusicController;
+
     QString mRootPath = ".";
 
     QQmlContext* mContext = Q_NULLPTR;
diff --git a/LenaPi/main.qml b/LenaPi/main.qml
index 938dae7..e541dd9 100644
--- a/LenaPi/main.qml
+++ b/LenaPi/main.qml
@@ -18,8 +18,7 @@ Window {
 
     Loader{
         anchors.fill: parent
-        //source: "MusicPlayer.qml"
-        source: "Navigation.qml"
+        source: uiStateModel.pSource
     }
 
 }
diff --git a/LenaPi/models/MusicModel.cpp b/LenaPi/models/MusicModel.cpp
new file mode 100644
index 0000000..8dc6652
--- /dev/null
+++ b/LenaPi/models/MusicModel.cpp
@@ -0,0 +1,32 @@
+#include "MusicModel.h"
+
+MusicModel::MusicModel(QObject *parent) : QObject(parent)
+{
+
+}
+
+void MusicModel::init(NavigationItemModel *item)
+{
+    mCurrentItem = item;
+    emit currentItemChanged();
+}
+
+void MusicModel::navigateBack()
+{
+    emit navigateTo(mCurrentItem);
+}
+
+void MusicModel::playPause()
+{
+    mIsPlaying = !mIsPlaying;
+}
+
+NavigationItemModel *MusicModel::getCurrentItem()
+{
+    return mCurrentItem;
+}
+
+bool MusicModel::isPlaying()
+{
+    return mIsPlaying;
+}
diff --git a/LenaPi/models/MusicModel.h b/LenaPi/models/MusicModel.h
new file mode 100644
index 0000000..9017625
--- /dev/null
+++ b/LenaPi/models/MusicModel.h
@@ -0,0 +1,35 @@
+#ifndef MUSICMODEL_H
+#define MUSICMODEL_H
+
+#include <QObject>
+
+#include <models/NavigationItemModel.h>
+
+class MusicModel : public QObject
+{
+    Q_OBJECT
+
+    Q_PROPERTY(QObject* pCurrentItem READ getCurrentItem NOTIFY currentItemChanged)
+
+signals:
+    void navigateTo(NavigationItemModel *item);
+    void currentItemChanged();
+
+public:
+    MusicModel(QObject *parent = Q_NULLPTR);
+
+    void init(NavigationItemModel* item);
+
+    Q_INVOKABLE void navigateBack();
+    Q_INVOKABLE void playPause();
+
+    NavigationItemModel *getCurrentItem();
+
+    bool isPlaying();
+
+private:
+    bool mIsPlaying = false;
+    NavigationItemModel* mCurrentItem = Q_NULLPTR;
+};
+
+#endif // MUSICMODEL_H
diff --git a/LenaPi/models/NavigationItemModel.cpp b/LenaPi/models/NavigationItemModel.cpp
index 298c546..e442515 100644
--- a/LenaPi/models/NavigationItemModel.cpp
+++ b/LenaPi/models/NavigationItemModel.cpp
@@ -7,6 +7,7 @@ NavigationItemModel::NavigationItemModel(QObject *parent) : QObject(parent),
     mImageSource("qrc:/default_image"),
     mParentItem(qobject_cast<NavigationItemModel*>(parent))
 {
+    qRegisterMetaType<NavigationItemModel*>("NavigationItemModel*");
 }
 
 QString NavigationItemModel::getImageSource() const
diff --git a/LenaPi/models/UiStateModel.cpp b/LenaPi/models/UiStateModel.cpp
new file mode 100644
index 0000000..ec44a07
--- /dev/null
+++ b/LenaPi/models/UiStateModel.cpp
@@ -0,0 +1,21 @@
+#include "UiStateModel.h"
+
+UiStateModel::UiStateModel(QObject *parent) : QObject(parent)
+{
+    showNavigation();
+}
+
+QUrl UiStateModel::getSource() const
+{
+    return mSource;
+}
+
+void UiStateModel::showMusicPlayer(){
+    mSource = QUrl("MusicPlayer.qml");
+    emit sourceChanged();
+}
+
+void UiStateModel::showNavigation(){
+    mSource = QUrl("Navigation.qml");
+    emit sourceChanged();
+}
diff --git a/LenaPi/models/UiStateModel.h b/LenaPi/models/UiStateModel.h
new file mode 100644
index 0000000..22d631d
--- /dev/null
+++ b/LenaPi/models/UiStateModel.h
@@ -0,0 +1,28 @@
+#ifndef UISTATEMODEL_H
+#define UISTATEMODEL_H
+
+#include <QObject>
+#include <QUrl>
+
+class UiStateModel : public QObject
+{
+    Q_OBJECT
+
+    Q_PROPERTY(QUrl pSource READ getSource NOTIFY sourceChanged)
+
+signals:
+    void sourceChanged();
+
+public:
+    UiStateModel(QObject *parent = Q_NULLPTR);
+
+    QUrl getSource() const;
+
+    void showMusicPlayer();
+    void showNavigation();
+
+private:
+    QUrl mSource;
+};
+
+#endif // UISTATEMODEL_H