diff --git a/tracker/gioui/buttons.go b/tracker/gioui/buttons.go
index 024ab10..11d337d 100644
--- a/tracker/gioui/buttons.go
+++ b/tracker/gioui/buttons.go
@@ -44,6 +44,14 @@ type (
 		TipArea   component.TipArea
 		Bool      tracker.Bool
 	}
+
+	MenuClickable struct {
+		Clickable Clickable
+		menu      Menu
+		Selected  tracker.OptionalInt
+		TipArea   component.TipArea
+		Tooltip   component.Tooltip
+	}
 )
 
 func NewActionClickable(a tracker.Action) *ActionClickable {
@@ -136,7 +144,10 @@ func ToggleButton(gtx C, th *material.Theme, b *BoolClickable, text string) Butt
 	ret := Button(th, &b.Clickable, text)
 	ret.Background = transparent
 	ret.Inset = layout.UniformInset(unit.Dp(6))
-	if b.Bool.Value() {
+	if !b.Bool.Enabled() {
+		ret.Color = disabledTextColor
+		ret.Background = transparent
+	} else if b.Bool.Value() {
 		ret.Color = th.Palette.ContrastFg
 		ret.Background = th.Palette.Fg
 	} else {
@@ -287,6 +298,7 @@ type ButtonStyle struct {
 	Inset        layout.Inset
 	Button       *Clickable
 	shaper       *text.Shaper
+	Hidden       bool
 }
 
 type ButtonLayoutStyle struct {
@@ -351,6 +363,9 @@ func (b ButtonStyle) Layout(gtx layout.Context) layout.Dimensions {
 		CornerRadius: b.CornerRadius,
 		Button:       b.Button,
 	}.Layout(gtx, func(gtx layout.Context) layout.Dimensions {
+		if b.Hidden {
+			return layout.Dimensions{}
+		}
 		return b.Inset.Layout(gtx, func(gtx layout.Context) layout.Dimensions {
 			colMacro := op.Record(gtx.Ops)
 			paint.ColorOp{Color: b.Color}.Add(gtx.Ops)
diff --git a/tracker/gioui/iconcache.go b/tracker/gioui/iconcache.go
index b79eadb..f663a2a 100644
--- a/tracker/gioui/iconcache.go
+++ b/tracker/gioui/iconcache.go
@@ -10,6 +10,9 @@ var iconCache = map[*byte]*widget.Icon{}
 
 // widgetForIcon returns a widget for IconVG data, but caching the results
 func widgetForIcon(icon []byte) *widget.Icon {
+	if icon == nil {
+		return nil
+	}
 	if widget, ok := iconCache[&icon[0]]; ok {
 		return widget
 	}
diff --git a/tracker/gioui/label.go b/tracker/gioui/label.go
index 1c2081a..5e78993 100644
--- a/tracker/gioui/label.go
+++ b/tracker/gioui/label.go
@@ -46,5 +46,17 @@ func (l LabelStyle) Layout(gtx layout.Context) layout.Dimensions {
 }
 
 func Label(str string, color color.NRGBA, shaper *text.Shaper) layout.Widget {
-	return LabelStyle{Text: str, Color: color, ShadeColor: black, Font: labelDefaultFont, FontSize: labelDefaultFontSize, Alignment: layout.W, Shaper: shaper}.Layout
+	return SizedLabel(str, color, shaper, labelDefaultFontSize)
+}
+
+func SizedLabel(str string, color color.NRGBA, shaper *text.Shaper, fontSize unit.Sp) layout.Widget {
+	return LabelStyle{
+		Text:       str,
+		Color:      color,
+		ShadeColor: black,
+		Font:       labelDefaultFont,
+		FontSize:   fontSize,
+		Alignment:  layout.W,
+		Shaper:     shaper,
+	}.Layout
 }
diff --git a/tracker/gioui/menu.go b/tracker/gioui/menu.go
index 3597d31..7c552b9 100644
--- a/tracker/gioui/menu.go
+++ b/tracker/gioui/menu.go
@@ -12,8 +12,6 @@ import (
 	"gioui.org/op/paint"
 	"gioui.org/text"
 	"gioui.org/unit"
-	"gioui.org/widget"
-	"gioui.org/widget/material"
 	"github.com/vsariola/sointu/tracker"
 )
 
@@ -103,12 +101,12 @@ func (m *MenuStyle) Layout(gtx C, items ...MenuItem) D {
 					}
 					icon := widgetForIcon(item.IconBytes)
 					iconColor := m.IconColor
-					if !item.Doer.Allowed() {
-						iconColor = mediumEmphasisTextColor
-					}
 					iconInset := layout.Inset{Left: unit.Dp(12), Right: unit.Dp(6)}
 					textLabel := LabelStyle{Text: item.Text, FontSize: m.FontSize, Color: m.TextColor, Shaper: m.Shaper}
 					if !item.Doer.Allowed() {
+						// note: might be a bug in gioui, but for iconColor = mediumEmphasisTextColor
+						// this does not render the icon at all. other colors seem to work fine.
+						iconColor = disabledTextColor
 						textLabel.Color = mediumEmphasisTextColor
 					}
 					shortcutLabel := LabelStyle{Text: item.ShortcutText, FontSize: m.FontSize, Color: m.ShortCutColor, Shaper: m.Shaper}
@@ -116,13 +114,18 @@ func (m *MenuStyle) Layout(gtx C, items ...MenuItem) D {
 					dims := layout.Flex{Axis: layout.Horizontal, Alignment: layout.Middle}.Layout(gtx,
 						layout.Rigid(func(gtx C) D {
 							return iconInset.Layout(gtx, func(gtx C) D {
-								p := gtx.Dp(unit.Dp(m.IconSize))
+								p := gtx.Dp(m.IconSize)
 								gtx.Constraints.Min = image.Pt(p, p)
+								if icon == nil {
+									return D{Size: gtx.Constraints.Min}
+								}
 								return icon.Layout(gtx, iconColor)
 							})
 						}),
 						layout.Rigid(textLabel.Layout),
-						layout.Flexed(1, func(gtx C) D { return D{Size: image.Pt(gtx.Constraints.Max.X, 1)} }),
+						layout.Flexed(1, func(gtx C) D {
+							return D{Size: image.Pt(gtx.Constraints.Max.X, 1)}
+						}),
 						layout.Rigid(func(gtx C) D {
 							return shortcutInset.Layout(gtx, shortcutLabel.Layout)
 						}),
@@ -168,14 +171,14 @@ func PopupMenu(menu *Menu, shaper *text.Shaper) MenuStyle {
 	}
 }
 
-func (tr *Tracker) layoutMenu(gtx C, title string, clickable *widget.Clickable, menu *Menu, width unit.Dp, items ...MenuItem) layout.Widget {
+func (tr *Tracker) layoutMenu(gtx C, title string, clickable *Clickable, menu *Menu, width unit.Dp, items ...MenuItem) layout.Widget {
 	for clickable.Clicked(gtx) {
 		menu.Visible = true
 	}
 	m := PopupMenu(menu, tr.Theme.Shaper)
 	return func(gtx C) D {
 		defer op.Offset(image.Point{}).Push(gtx.Ops).Pop()
-		titleBtn := material.Button(tr.Theme, clickable, title)
+		titleBtn := Button(tr.Theme, clickable, title)
 		titleBtn.Color = white
 		titleBtn.Background = transparent
 		titleBtn.CornerRadius = unit.Dp(0)
diff --git a/tracker/gioui/note_editor.go b/tracker/gioui/note_editor.go
index 0006878..764b544 100644
--- a/tracker/gioui/note_editor.go
+++ b/tracker/gioui/note_editor.go
@@ -158,11 +158,7 @@ func (te *NoteEditor) layoutButtons(gtx C, t *Tracker) D {
 		deleteTrackBtnStyle := ActionIcon(gtx, t.Theme, te.DeleteTrackBtn, icons.ActionDelete, te.deleteTrackHint)
 		splitTrackBtnStyle := ActionIcon(gtx, t.Theme, te.SplitTrackBtn, icons.CommunicationCallSplit, te.splitTrackHint)
 		newTrackBtnStyle := ActionIcon(gtx, t.Theme, te.NewTrackBtn, icons.ContentAdd, te.addTrackHint)
-		in := layout.UniformInset(unit.Dp(1))
-		voiceUpDown := func(gtx C) D {
-			numStyle := NumericUpDown(t.Theme, te.TrackVoices, "Number of voices for this track")
-			return in.Layout(gtx, numStyle.Layout)
-		}
+		voiceUpDown := NumericUpDownPadded(t.Theme, te.TrackVoices, "Number of voices for this track", 1)
 		effectBtnStyle := ToggleButton(gtx, t.Theme, te.EffectBtn, "Hex")
 		uniqueBtnStyle := ToggleIcon(gtx, t.Theme, te.UniqueBtn, icons.ToggleStarBorder, icons.ToggleStar, te.uniqueOffTip, te.uniqueOnTip)
 		midiInBtnStyle := ToggleButton(gtx, t.Theme, te.TrackMidiInBtn, "MIDI")
@@ -176,7 +172,7 @@ func (te *NoteEditor) layoutButtons(gtx C, t *Tracker) D {
 			layout.Rigid(effectBtnStyle.Layout),
 			layout.Rigid(uniqueBtnStyle.Layout),
 			layout.Rigid(Label("  Voices:", white, t.Theme.Shaper)),
-			layout.Rigid(voiceUpDown),
+			layout.Rigid(voiceUpDown.Layout),
 			layout.Rigid(splitTrackBtnStyle.Layout),
 			layout.Flexed(1, func(gtx C) D { return layout.Dimensions{Size: gtx.Constraints.Min} }),
 			layout.Rigid(midiInBtnStyle.Layout),
@@ -287,15 +283,15 @@ func (te *NoteEditor) layoutTracks(gtx C, t *Tracker) D {
 				c = cursorColor
 			}
 			if hasTrackMidiIn {
-				c = cursorForTrackMidiInColor
+				c = trackMidiInCurrentColor
 			}
-			te.paintColumnCell(gtx, x, t, c)
+			te.paintColumnCell(gtx, x, t, c, hasTrackMidiIn)
 		}
 		// draw the corresponding "fake cursors" for instrument-track-groups (for polyphony)
-		if hasTrackMidiIn {
+		if hasTrackMidiIn && y == cursor.Y {
 			for _, trackIndex := range t.Model.TracksWithSameInstrumentAsCurrent() {
-				if x == trackIndex && y == cursor.Y {
-					te.paintColumnCell(gtx, x, t, cursorNeighborForTrackMidiInColor)
+				if x == trackIndex {
+					te.paintColumnCell(gtx, x, t, trackMidiInAdditionalColor, hasTrackMidiIn)
 				}
 			}
 		}
@@ -334,10 +330,10 @@ func (te *NoteEditor) layoutTracks(gtx C, t *Tracker) D {
 	return table.Layout(gtx)
 }
 
-func (te *NoteEditor) paintColumnCell(gtx C, x int, t *Tracker, c color.NRGBA) {
+func (te *NoteEditor) paintColumnCell(gtx C, x int, t *Tracker, c color.NRGBA, ignoreEffect bool) {
 	cw := gtx.Constraints.Min.X
 	cx := 0
-	if t.Model.Notes().Effect(x) {
+	if t.Model.Notes().Effect(x) && !ignoreEffect {
 		cw /= 2
 		if t.Model.Notes().LowNibble() {
 			cx += cw
diff --git a/tracker/gioui/numericupdown.go b/tracker/gioui/numericupdown.go
index 3b788bc..b1a86cd 100644
--- a/tracker/gioui/numericupdown.go
+++ b/tracker/gioui/numericupdown.go
@@ -48,7 +48,9 @@ type NumericUpDownStyle struct {
 	Tooltip         component.Tooltip
 	Width           unit.Dp
 	Height          unit.Dp
+	Padding         unit.Dp
 	shaper          text.Shaper
+	Hidden          bool
 }
 
 func NewNumberInput(v tracker.Int) *NumberInput {
@@ -56,6 +58,10 @@ func NewNumberInput(v tracker.Int) *NumberInput {
 }
 
 func NumericUpDown(th *material.Theme, number *NumberInput, tooltip string) NumericUpDownStyle {
+	return NumericUpDownPadded(th, number, tooltip, 0)
+}
+
+func NumericUpDownPadded(th *material.Theme, number *NumberInput, tooltip string, padding int) NumericUpDownStyle {
 	bgColor := th.Palette.Fg
 	bgColor.R /= 4
 	bgColor.G /= 4
@@ -74,11 +80,22 @@ func NumericUpDown(th *material.Theme, number *NumberInput, tooltip string) Nume
 		Tooltip:         Tooltip(th, tooltip),
 		Width:           unit.Dp(70),
 		Height:          unit.Dp(20),
+		Padding:         unit.Dp(padding),
 		shaper:          *th.Shaper,
 	}
 }
 
 func (s *NumericUpDownStyle) Layout(gtx C) D {
+	if s.Hidden {
+		return D{}
+	}
+	if s.Padding <= 0 {
+		return s.layoutWithTooltip(gtx)
+	}
+	return layout.UniformInset(s.Padding).Layout(gtx, s.layoutWithTooltip)
+}
+
+func (s *NumericUpDownStyle) layoutWithTooltip(gtx C) D {
 	if s.Tooltip.Text.Text != "" {
 		return s.NumberInput.tipArea.Layout(gtx, s.Tooltip, s.actualLayout)
 	}
diff --git a/tracker/gioui/songpanel.go b/tracker/gioui/songpanel.go
index b3ddac8..e08fa7f 100644
--- a/tracker/gioui/songpanel.go
+++ b/tracker/gioui/songpanel.go
@@ -7,14 +7,13 @@ import (
 	"gioui.org/op/clip"
 	"gioui.org/op/paint"
 	"gioui.org/unit"
-	"gioui.org/widget"
 	"github.com/vsariola/sointu/tracker"
 	"github.com/vsariola/sointu/version"
 	"golang.org/x/exp/shiny/materialdesign/icons"
 )
 
 type SongPanel struct {
-	MenuBar        []widget.Clickable
+	MenuBar        []Clickable
 	Menus          []Menu
 	BPM            *NumberInput
 	RowsPerPattern *NumberInput
@@ -57,7 +56,7 @@ type SongPanel struct {
 
 func NewSongPanel(model *tracker.Model) *SongPanel {
 	ret := &SongPanel{
-		MenuBar:        make([]widget.Clickable, 3),
+		MenuBar:        make([]Clickable, 3),
 		Menus:          make([]Menu, 3),
 		BPM:            NewNumberInput(model.BPM().Int()),
 		RowsPerPattern: NewNumberInput(model.RowsPerPattern().Int()),
diff --git a/tracker/gioui/theme.go b/tracker/gioui/theme.go
index 1df08c7..9beffc0 100644
--- a/tracker/gioui/theme.go
+++ b/tracker/gioui/theme.go
@@ -60,8 +60,10 @@ var activeLightSurfaceColor = color.NRGBA{R: 45, G: 45, B: 45, A: 255}
 var cursorColor = color.NRGBA{R: 100, G: 140, B: 255, A: 48}
 var selectionColor = color.NRGBA{R: 100, G: 140, B: 255, A: 12}
 var inactiveSelectionColor = color.NRGBA{R: 140, G: 140, B: 140, A: 16}
-var cursorForTrackMidiInColor = color.NRGBA{R: 255, G: 100, B: 140, A: 48}
-var cursorNeighborForTrackMidiInColor = color.NRGBA{R: 255, G: 100, B: 140, A: 24}
+
+var trackMidiInCurrentColor = color.NRGBA{R: 255, G: 100, B: 140, A: 48}
+var trackMidiInAdditionalColor = withScaledAlpha(trackMidiInCurrentColor, 0.7)
+var trackMidiVelInColor = withScaledAlpha(trackMidiInCurrentColor, 0.3)
 
 var errorColor = color.NRGBA{R: 207, G: 102, B: 121, A: 255}
 
@@ -75,3 +77,13 @@ var dialogBgColor = color.NRGBA{R: 0, G: 0, B: 0, A: 224}
 
 var paramIsSendTargetColor = color.NRGBA{R: 120, G: 120, B: 210, A: 255}
 var paramValueInvalidColor = color.NRGBA{R: 120, G: 120, B: 120, A: 190}
+
+func withScaledAlpha(c color.NRGBA, factor float32) color.NRGBA {
+	A := factor * float32(c.A)
+	return color.NRGBA{
+		R: c.R,
+		G: c.G,
+		B: c.B,
+		A: uint8(A),
+	}
+}
diff --git a/tracker/gioui/tracker.go b/tracker/gioui/tracker.go
index f104924..b6f540e 100644
--- a/tracker/gioui/tracker.go
+++ b/tracker/gioui/tracker.go
@@ -101,9 +101,7 @@ func NewTracker(model *tracker.Model) *Tracker {
 
 func (t *Tracker) Main() {
 	titleFooter := ""
-	w := new(app.Window)
-	w.Option(app.Title("Sointu Tracker"))
-	w.Option(app.Size(unit.Dp(800), unit.Dp(600)))
+	w := NewWindow()
 	t.InstrumentEditor.Focus()
 	recoveryTicker := time.NewTicker(time.Second * 30)
 	t.Explorer = explorer.NewExplorer(w)
@@ -127,9 +125,7 @@ func (t *Tracker) Main() {
 				}
 				if !t.Quitted() {
 					// TODO: uh oh, there's no way of canceling the destroyevent in gioui? so we create a new window just to show the dialog
-					w = new(app.Window)
-					w.Option(app.Title("Sointu Tracker"))
-					w.Option(app.Size(unit.Dp(800), unit.Dp(600)))
+					w = NewWindow()
 					t.Explorer = explorer.NewExplorer(w)
 					go eventLoop(w, events, acks)
 				}
@@ -165,6 +161,16 @@ func (t *Tracker) Main() {
 	t.quitWG.Done()
 }
 
+func NewWindow() *app.Window {
+	w := new(app.Window)
+	w.Option(app.Title("Sointu Tracker"))
+	w.Option(
+		app.Size(unit.Dp(800), unit.Dp(600)),
+		app.Fullscreen.Option(),
+	)
+	return w
+}
+
 func eventLoop(w *app.Window, events chan<- event.Event, acks <-chan struct{}) {
 	// Iterate window events, sending each to the old event loop and waiting for
 	// a signal that processing is complete before iterating again.
diff --git a/tracker/gioui/unit_editor.go b/tracker/gioui/unit_editor.go
index bd65463..3ff8ed7 100644
--- a/tracker/gioui/unit_editor.go
+++ b/tracker/gioui/unit_editor.go
@@ -32,7 +32,7 @@ type UnitEditor struct {
 	CopyUnitBtn    *TipClickable
 	ClearUnitBtn   *ActionClickable
 	DisableUnitBtn *BoolClickable
-	SelectTypeBtn  *widget.Clickable
+	SelectTypeBtn  *Clickable
 	commentEditor  *Editor
 	caser          cases.Caser
 
@@ -47,7 +47,7 @@ func NewUnitEditor(m *tracker.Model) *UnitEditor {
 		ClearUnitBtn:   NewActionClickable(m.ClearUnit()),
 		DisableUnitBtn: NewBoolClickable(m.UnitDisabled().Bool()),
 		CopyUnitBtn:    new(TipClickable),
-		SelectTypeBtn:  new(widget.Clickable),
+		SelectTypeBtn:  new(Clickable),
 		commentEditor:  NewEditor(widget.Editor{SingleLine: true, Submit: true}),
 		sliderList:     NewDragList(m.Params().List(), layout.Vertical),
 		searchList:     NewDragList(m.SearchResults().List(), layout.Vertical),
@@ -236,9 +236,9 @@ func (pe *UnitEditor) command(e key.Event, t *Tracker) {
 type ParameterWidget struct {
 	floatWidget widget.Float
 	boolWidget  widget.Bool
-	instrBtn    widget.Clickable
+	instrBtn    Clickable
 	instrMenu   Menu
-	unitBtn     widget.Clickable
+	unitBtn     Clickable
 	unitMenu    Menu
 	Parameter   tracker.Parameter
 	tipArea     component.TipArea
@@ -332,7 +332,6 @@ func (p ParameterStyle) Layout(gtx C) D {
 				gtx.Constraints.Min.Y = gtx.Dp(unit.Dp(40))
 				instrItems := make([]MenuItem, p.tracker.Instruments().Count())
 				for i := range instrItems {
-					i := i
 					name, _, _, _ := p.tracker.Instruments().Item(i)
 					instrItems[i].Text = name
 					instrItems[i].IconBytes = icons.NavigationChevronRight
diff --git a/tracker/optional_int.go b/tracker/optional_int.go
new file mode 100644
index 0000000..dbdfaa3
--- /dev/null
+++ b/tracker/optional_int.go
@@ -0,0 +1,42 @@
+package tracker
+
+type (
+	// OptionalInt tries to follow the same convention as e.g. Int{...} or Bool{...}
+	// Do not confuse with types.OptionalInteger, which you might use as a model,
+	// but don't necessarily have to.
+	OptionalInt struct {
+		optionalIntData
+	}
+
+	optionalIntData interface {
+		Unpack() (int, bool)
+		Value() int
+		Range() intRange
+
+		setValue(int)
+		unsetValue()
+		change(kind string) func()
+	}
+
+	TrackMidiVelIn Model
+)
+
+func (v OptionalInt) Set(value int, present bool) (ok bool) {
+	if !present {
+		v.unsetValue()
+		return true
+	}
+	// TODO: can we deduplicate this by referencing Int{...}.Set(value) ?
+	r := v.Range()
+	if v.Equals(value, present) || value < r.Min || value > r.Max {
+		return false
+	}
+	defer v.change("Set")()
+	v.setValue(value)
+	return true
+}
+
+func (v OptionalInt) Equals(value int, present bool) bool {
+	oldValue, oldPresent := v.Unpack()
+	return value == oldValue && present == oldPresent
+}
diff --git a/tracker/types/optional.go b/tracker/types/optional.go
new file mode 100644
index 0000000..7b36690
--- /dev/null
+++ b/tracker/types/optional.go
@@ -0,0 +1,47 @@
+package types
+
+type (
+	// OptionalInteger is the simple struct, not to be confused with tracker.OptionalInt.
+	// It implements the tracker.optionalIntData interface, without needing to know so.
+	OptionalInteger struct {
+		value  int
+		exists bool
+	}
+)
+
+func NewOptionalInteger(value int, exists bool) OptionalInteger {
+	return OptionalInteger{value, exists}
+}
+
+func NewOptionalIntegerOf(value int) OptionalInteger {
+	return OptionalInteger{
+		value:  value,
+		exists: true,
+	}
+}
+
+func NewEmptyOptionalInteger() OptionalInteger {
+	// could also just use OptionalInteger{}
+	return OptionalInteger{
+		exists: false,
+	}
+}
+
+func (i OptionalInteger) Unpack() (int, bool) {
+	return i.value, i.exists
+}
+
+func (i OptionalInteger) Value() int {
+	if !i.exists {
+		panic("Access value of empty OptionalInteger")
+	}
+	return i.value
+}
+
+func (i OptionalInteger) Empty() bool {
+	return !i.exists
+}
+
+func (i OptionalInteger) Equals(value int) bool {
+	return i.exists && i.value == value
+}