diff --git a/include/PianoRoll.h b/include/PianoRoll.h
index bc2a0d8cb1b..8f1dabdc350 100644
--- a/include/PianoRoll.h
+++ b/include/PianoRoll.h
@@ -295,7 +295,7 @@ protected slots:
 
 	int m_oldNotesEditHeight;
 	int m_notesEditHeight;
-	int m_ppt;
+	int m_ppt;  // pixels per tact
 	int m_totalKeysToScroll;
 
 	// remember these values to use them
diff --git a/include/Plugin.h b/include/Plugin.h
index b73238ab5c7..40a075c67ac 100644
--- a/include/Plugin.h
+++ b/include/Plugin.h
@@ -134,7 +134,7 @@ class EXPORT Plugin : public Model, public JournallingObject
 			const Plugin::PluginTypes m_type;
 		} ;
 
-		SubPluginFeatures * subPluginFeatures;
+		SubPluginFeatures *subPluginFeatures;
 
 	} ;
 
@@ -148,7 +148,9 @@ class EXPORT Plugin : public Model, public JournallingObject
 	// returns display-name out of descriptor
 	virtual QString displayName() const
 	{
-		return Model::displayName().isEmpty() ?  m_descriptor->displayName : Model::displayName();
+		return Model::displayName().isEmpty()
+				? m_descriptor->displayName
+				: Model::displayName();
 	}
 
 	// return plugin-type
@@ -173,13 +175,13 @@ class EXPORT Plugin : public Model, public JournallingObject
 
 	// returns an instance of a plugin whose name matches to given one
 	// if specified plugin couldn't be loaded, it creates a dummy-plugin
-	static Plugin * instantiate( const QString& pluginName, Model * parent, void * data );
+	static Plugin * instantiate( const QString& pluginName, Model *parent, void * data );
 
 	// fills given list with descriptors of all available plugins
 	static void getDescriptorsOfAvailPlugins( DescriptorList& pluginDescriptors );
 
 	// create a view for the model 
-	PluginView * createView( QWidget* parent );
+	PluginView* createView( QWidget* parent );
 
 
 protected:
diff --git a/include/lmms_basics.h b/include/lmms_basics.h
index bdd72f4fab7..ea02f77d183 100644
--- a/include/lmms_basics.h
+++ b/include/lmms_basics.h
@@ -78,9 +78,9 @@ struct typeInfo
 		return 1;
 	}
 
-	static inline bool isEqual( T _x, T _y )
+	static inline bool isEqual( T x, T y )
 	{
-		return _x == _y;
+		return x == y;
 	}
 
 	static inline T absVal( T t )
@@ -97,13 +97,13 @@ inline float typeInfo<float>::minEps()
 }
 
 template<>
-inline bool typeInfo<float>::isEqual( float _x, float _y )
+inline bool typeInfo<float>::isEqual( float x, float y )
 {
-	if( likely( _x == _y ) )
+	if( x == y )
 	{
 		return true;
 	}
-	return absVal( _x - _y ) < minEps();
+	return absVal( x - y ) < minEps();
 }
 
 
diff --git a/src/gui/MainWindow.cpp b/src/gui/MainWindow.cpp
index 612a7409e63..cccc7bd398f 100644
--- a/src/gui/MainWindow.cpp
+++ b/src/gui/MainWindow.cpp
@@ -83,7 +83,6 @@ MainWindow::MainWindow() :
 	vbox->setSpacing( 0 );
 	vbox->setMargin( 0 );
 
-
 	QWidget * w = new QWidget( main_widget );
 	QHBoxLayout * hbox = new QHBoxLayout( w );
 	hbox->setSpacing( 0 );
@@ -94,24 +93,25 @@ MainWindow::MainWindow() :
 	QSplitter * splitter = new QSplitter( Qt::Horizontal, w );
 	splitter->setChildrenCollapsible( false );
 
-	QString wdir = ConfigManager::inst()->workingDir();
+	ConfigManager* confMgr = ConfigManager::inst();
+
 	sideBar->appendTab( new PluginBrowser( splitter ) );
 	sideBar->appendTab( new FileBrowser(
-				ConfigManager::inst()->userProjectsDir() + "*" +
-				ConfigManager::inst()->factoryProjectsDir(),
+				confMgr->userProjectsDir() + "*" +
+				confMgr->factoryProjectsDir(),
 					"*.mmp *.mmpz *.xml *.mid *.flp",
 							tr( "My Projects" ),
 					embed::getIconPixmap( "project_file" ).transformed( QTransform().rotate( 90 ) ),
 							splitter, false, true ) );
 	sideBar->appendTab( new FileBrowser(
-				ConfigManager::inst()->userSamplesDir() + "*" +
-				ConfigManager::inst()->factorySamplesDir(),
+				confMgr->userSamplesDir() + "*" +
+				confMgr->factorySamplesDir(),
 					"*", tr( "My Samples" ),
 					embed::getIconPixmap( "sample_file" ).transformed( QTransform().rotate( 90 ) ),
 							splitter, false, true ) );
 	sideBar->appendTab( new FileBrowser(
-				ConfigManager::inst()->userPresetsDir() + "*" +
-				ConfigManager::inst()->factoryPresetsDir(),
+				confMgr->userPresetsDir() + "*" +
+				confMgr->factoryPresetsDir(),
 					"*.xpf *.cs.xml *.xiz",
 					tr( "My Presets" ),
 					embed::getIconPixmap( "preset_file" ).transformed( QTransform().rotate( 90 ) ),
@@ -121,33 +121,30 @@ MainWindow::MainWindow() :
 					embed::getIconPixmap( "home" ).transformed( QTransform().rotate( 90 ) ),
 							splitter, false, true ) );
 
+
 	QStringList root_paths;
+	QString title = tr( "Root directory" );
+	bool dirs_as_items = false;
+
 #ifdef LMMS_BUILD_APPLE
+	title = tr( "Volumes" );
 	root_paths += "/Volumes";
-#else
+#elif defined(LMMS_BUILD_WIN32)
+	title = tr( "My Computer" );
+	dirs_as_items = true;
+#endif
+
+#if ! defined(LMMS_BUILD_APPLE)
 	QFileInfoList drives = QDir::drives();
 	foreach( const QFileInfo & drive, drives )
 	{
 		root_paths += drive.absolutePath();
 	}
 #endif
-	sideBar->appendTab( new FileBrowser( root_paths.join( "*" ), "*",
-#ifdef LMMS_BUILD_WIN32
-							tr( "My Computer" ),
-#elif defined(LMMS_BUILD_APPLE)
-							tr( "Volumes" ),
-#else
-							tr( "Root Directory" ),
-#endif
 
+	sideBar->appendTab( new FileBrowser( root_paths.join( "*" ), "*", title,
 					embed::getIconPixmap( "computer" ).transformed( QTransform().rotate( 90 ) ),
-							splitter,
-#ifdef LMMS_BUILD_WIN32
-							true
-#else
-							false
-#endif
-								) );
+							splitter, dirs_as_items) );
 
 	m_workspace = new QMdiArea( splitter );
 
@@ -190,13 +187,13 @@ MainWindow::MainWindow() :
 	vbox->addWidget( w );
 	setCentralWidget( main_widget );
 
-	m_updateTimer.start( 1000 / 20, this );	// 20 fps
+	m_updateTimer.start( 1000 / 20, this );  // 20 fps
 
 	if( ConfigManager::inst()->value( "ui", "enableautosave" ).toInt() )
 	{
 		// connect auto save
 		connect(&m_autoSaveTimer, SIGNAL(timeout()), this, SLOT(autoSave()));
-		m_autoSaveTimer.start(1000 * 60); // 1 minute
+		m_autoSaveTimer.start(1000 * 60);  // 1 minute
 	}
 
 	connect( Engine::getSong(), SIGNAL( playbackStateChanged() ),
@@ -208,12 +205,10 @@ MainWindow::MainWindow() :
 
 MainWindow::~MainWindow()
 {
-	for( QList<PluginView *>::iterator it = m_tools.begin();
-						it != m_tools.end(); ++it )
+	for( PluginView *view : m_tools )
 	{
-		Model * m = ( *it )->model();
-		delete *it;
-		delete m;
+		delete view->model();
+		delete view;
 	}
 	// TODO: Close tools
 	// destroy engine which will do further cleanups etc.
diff --git a/src/gui/PluginBrowser.cpp b/src/gui/PluginBrowser.cpp
index 5c10dd368ac..96f33ae7501 100644
--- a/src/gui/PluginBrowser.cpp
+++ b/src/gui/PluginBrowser.cpp
@@ -88,8 +88,6 @@ PluginBrowser::~PluginBrowser()
 
 
 
-
-
 PluginDescList::PluginDescList(QWidget *parent) :
 	QWidget(parent)
 {
@@ -98,7 +96,6 @@ PluginDescList::PluginDescList(QWidget *parent) :
 	Plugin::getDescriptorsOfAvailPlugins( m_pluginDescriptors );
 	std::sort(m_pluginDescriptors.begin(), m_pluginDescriptors.end(), pluginBefore);
 
-
 	for( Plugin::DescriptorList::const_iterator it = m_pluginDescriptors.constBegin();
 		it != m_pluginDescriptors.constEnd(); ++it )
 	{
@@ -117,8 +114,6 @@ PluginDescList::PluginDescList(QWidget *parent) :
 
 
 
-
-
 PluginDescWidget::PluginDescWidget( const Plugin::Descriptor & _pd,
 							QWidget * _parent ) :
 	QWidget( _parent ),
@@ -181,7 +176,6 @@ void PluginDescWidget::paintEvent( QPaintEvent * )
 			m_targetHeight = qMax( 60, 25 + br.height() );
 		}
 	}
-
 }
 
 
@@ -237,6 +231,7 @@ void PluginDescWidget::updateHeight()
 		m_updateTimer.stop();
 		return;
 	}
+
 	if( !m_updateTimer.isActive() )
 	{
 		m_updateTimer.start( 15 );
diff --git a/src/gui/editors/PianoRoll.cpp b/src/gui/editors/PianoRoll.cpp
index d837292b71e..928752ace0c 100644
--- a/src/gui/editors/PianoRoll.cpp
+++ b/src/gui/editors/PianoRoll.cpp
@@ -375,7 +375,8 @@ PianoRoll::PianoRoll() :
 					this, SLOT( quantizeChanged() ) );
 
 	// Set up scale model
-	const auto& chord_table = InstrumentFunctionNoteStacking::ChordTable::getInstance();
+	const InstrumentFunctionNoteStacking::ChordTable& chord_table =
+			InstrumentFunctionNoteStacking::ChordTable::getInstance();
 
 	m_scaleModel.addItem( tr("No scale") );
 	for( const InstrumentFunctionNoteStacking::Chord& chord : chord_table )
@@ -3814,7 +3815,8 @@ int PianoRoll::quantization() const
 
 void PianoRoll::updateSemiToneMarkerMenu()
 {
-	const auto& chord_table = InstrumentFunctionNoteStacking::ChordTable::getInstance();
+	const InstrumentFunctionNoteStacking::ChordTable& chord_table =
+			InstrumentFunctionNoteStacking::ChordTable::getInstance();
 	const InstrumentFunctionNoteStacking::Chord& scale =
 			chord_table.getScaleByName( m_scaleModel.currentText() );
 	const InstrumentFunctionNoteStacking::Chord& chord =
diff --git a/src/gui/embed.cpp b/src/gui/embed.cpp
index 08af0c0a2cf..4e6ecaa13b7 100644
--- a/src/gui/embed.cpp
+++ b/src/gui/embed.cpp
@@ -45,73 +45,70 @@ namespace
 #include "embedded_resources.h"
 
 
-QPixmap getIconPixmap( const char * _name, int _w, int _h )
+QPixmap getIconPixmap( const char * pixmapName, int width, int height )
 {
-	if( _w == -1 || _h == -1 )
+	if( width == -1 || height == -1 )
 	{
-	        // Return cached pixmap
-                QPixmap cached = s_pixmapCache.value( _name );
+		// Return cached pixmap
+		QPixmap cached = s_pixmapCache.value( pixmapName );
 		if( !cached.isNull() )
 		{
 			return cached;
 		}
 
 		// Or try to load it
-		QList<QByteArray> formats = 
-			QImageReader::supportedImageFormats();
+		QList<QByteArray> formats = QImageReader::supportedImageFormats();
 		QList<QString> candidates;
-		QPixmap p;
+		QPixmap pixmap;
 		QString name;
 		int i;
 		
-		for ( i = 0; i < formats.size() && p.isNull(); ++i )  
+		for ( i = 0; i < formats.size() && pixmap.isNull(); ++i )  
 		{
-			candidates << QString( _name ) + "." + formats.at( i ).data();
+			candidates << QString( pixmapName ) + "." + formats.at( i ).data();
 		}
 
 #ifdef PLUGIN_NAME
-		for ( i = 0; i < candidates.size() && p.isNull(); ++i )  {
+		for ( i = 0; i < candidates.size() && pixmap.isNull(); ++i )  {
 			name = candidates.at( i );
-			p = QPixmap( ConfigManager::inst()->artworkDir() + "plugins/" +
+			pixmap = QPixmap( ConfigManager::inst()->artworkDir() + "plugins/" +
 				     STRINGIFY( PLUGIN_NAME ) + "_" + name );
 		}
 #endif
-		for ( i = 0; i < candidates.size() && p.isNull(); ++i )  {
+		for ( i = 0; i < candidates.size() && pixmap.isNull(); ++i )  {
 			name = candidates.at( i );
-			p = QPixmap( ConfigManager::inst()->artworkDir() + name );
+			pixmap = QPixmap( ConfigManager::inst()->artworkDir() + name );
 		}
 		
 		// nothing found, so look in default-artwork-dir
-		for ( i = 0; i < candidates.size() && p.isNull(); ++i )  {
+		for ( i = 0; i < candidates.size() && pixmap.isNull(); ++i )  {
 			name = candidates.at( i );
-			p = QPixmap( ConfigManager::inst()->defaultArtworkDir() 
-				     + name );
+			pixmap = QPixmap( ConfigManager::inst()->defaultArtworkDir() + name );
 		}
 		
-		for ( i = 0; i < candidates.size() && p.isNull(); ++i )  {
+		for ( i = 0; i < candidates.size() && pixmap.isNull(); ++i )  {
 			name = candidates.at( i );
 			const embed::descriptor & e = 
 				findEmbeddedData( name.toUtf8().constData() );
 			// found?
-			if( QString( e.name ) == name )
+			if( name == e.name )
 			{
-				p.loadFromData( e.data, e.size );
+				pixmap.loadFromData( e.data, e.size );
 			}
 		}
 		
 		// Fallback
-		if(p.isNull()) 
+		if( pixmap.isNull() )
 		{
-			p = QPixmap( 1, 1 );
+			pixmap = QPixmap( 1, 1 );
 		}
 		// Save to cache and return
-		s_pixmapCache.insert( _name, p );
-		return p;
-
+		s_pixmapCache.insert( pixmapName, pixmap );
+		return pixmap;
 	}
 
-	return getIconPixmap( _name ).
-		scaled( _w, _h, Qt::IgnoreAspectRatio, 
+	return getIconPixmap( pixmapName ).
+		scaled( width, height, Qt::IgnoreAspectRatio,
 			Qt::SmoothTransformation );
 }
 
diff --git a/src/gui/widgets/SideBar.cpp b/src/gui/widgets/SideBar.cpp
index 409fbf771ed..990bae7f651 100644
--- a/src/gui/widgets/SideBar.cpp
+++ b/src/gui/widgets/SideBar.cpp
@@ -107,53 +107,56 @@ SideBar::~SideBar()
 
 
 
-void SideBar::appendTab( SideBarWidget * _sbw )
+void SideBar::appendTab( SideBarWidget *widget )
 {
-	SideBarButton * btn = new SideBarButton( orientation(), this );
-	btn->setText( _sbw->title() );
-	btn->setIcon( _sbw->icon() );
-	btn->setCheckable( true );
-	m_widgets[btn] = _sbw;
-	m_btnGroup.addButton( btn );
-	addWidget( btn );
-
-	_sbw->hide();
-	_sbw->setMinimumWidth( 200 );
-
-	ToolTip::add( btn, _sbw->title() );
+	SideBarButton *button = new SideBarButton( orientation(), this );
+	button->setText( widget->title() );
+	button->setIcon( widget->icon() );
+	button->setCheckable( true );
+	m_widgets[button] = widget;
+	m_btnGroup.addButton( button );
+	addWidget( button );
+
+	widget->hide();
+	widget->setMinimumWidth( 200 );
+
+	ToolTip::add( button, widget->title() );
 }
 
 
 
 
-void SideBar::toggleButton( QAbstractButton * _btn )
+void SideBar::toggleButton( QAbstractButton * button )
 {
-	QToolButton * toolButton = NULL;
-	QWidget * activeWidget = NULL;
-	for( ButtonMap::Iterator it = m_widgets.begin();
-							it != m_widgets.end(); ++it )
+	QToolButton *toolButton = NULL;
+	QWidget *activeWidget = NULL;
+
+	for( auto it = m_widgets.begin(); it != m_widgets.end(); ++it )
 	{
-		QToolButton * curBtn = it.key();
-		if( curBtn != _btn )
+		QToolButton *curBtn = it.key();
+		QWidget *curWidget = it.value();
+
+		if( curBtn == button )
 		{
-			curBtn->setChecked( false );
-			curBtn->setToolButtonStyle( Qt::ToolButtonIconOnly );
+			toolButton = curBtn;
+			activeWidget = curWidget;
 		}
 		else
 		{
-			toolButton = it.key();
-			activeWidget = it.value();
+			curBtn->setChecked( false );
+			curBtn->setToolButtonStyle( Qt::ToolButtonIconOnly );
 		}
-		if( it.value() )
+
+		if( curWidget )
 		{
-			it.value()->hide();
+			curWidget->hide();
 		}
 	}
 
 	if( toolButton && activeWidget )
 	{
-		activeWidget->setVisible( _btn->isChecked() );
-		toolButton->setToolButtonStyle( _btn->isChecked() ?
+		activeWidget->setVisible( button->isChecked() );
+		toolButton->setToolButtonStyle( button->isChecked() ?
 				Qt::ToolButtonTextBesideIcon : Qt::ToolButtonIconOnly );
 	}
 }