diff --git a/cmd/synthers.go b/cmd/synthers.go
index 7da1d1c..cec6412 100644
--- a/cmd/synthers.go
+++ b/cmd/synthers.go
@@ -5,7 +5,4 @@ import (
 	"github.com/vsariola/sointu/vm"
 )
 
-var Synthers = []sointu.Synther{
-	vm.GoSynther{},
-	vm.MakeMultithreadSynther(vm.GoSynther{}),
-}
+var Synthers = []sointu.Synther{vm.GoSynther{}}
diff --git a/cmd/synthers_native.go b/cmd/synthers_native.go
index 3ef7009..a03c126 100644
--- a/cmd/synthers_native.go
+++ b/cmd/synthers_native.go
@@ -3,11 +3,9 @@
 package cmd
 
 import (
-	"github.com/vsariola/sointu/vm"
 	"github.com/vsariola/sointu/vm/compiler/bridge"
 )
 
 func init() {
 	Synthers = append(Synthers, bridge.NativeSynther{})
-	Synthers = append(Synthers, vm.MakeMultithreadSynther(bridge.NativeSynther{}))
 }
diff --git a/tracker/gioui/song_panel.go b/tracker/gioui/song_panel.go
index f08a3aa..af22dbc 100644
--- a/tracker/gioui/song_panel.go
+++ b/tracker/gioui/song_panel.go
@@ -31,9 +31,10 @@ type SongPanel struct {
 	CPUExpander          *Expander
 	SpectrumExpander     *Expander
 
-	WeightingTypeBtn *Clickable
-	OversamplingBtn  *Clickable
-	SynthBtn         *Clickable
+	WeightingTypeBtn  *Clickable
+	OversamplingBtn   *Clickable
+	SynthBtn          *Clickable
+	MultithreadingBtn *Clickable
 
 	BPM            *NumericUpDownState
 	RowsPerPattern *NumericUpDownState
@@ -67,9 +68,10 @@ func NewSongPanel(tr *Tracker) *SongPanel {
 		MenuBar:        NewMenuBar(tr),
 		PlayBar:        NewPlayBar(),
 
-		WeightingTypeBtn: new(Clickable),
-		OversamplingBtn:  new(Clickable),
-		SynthBtn:         new(Clickable),
+		WeightingTypeBtn:  new(Clickable),
+		OversamplingBtn:   new(Clickable),
+		SynthBtn:          new(Clickable),
+		MultithreadingBtn: new(Clickable),
 
 		SongSettingsExpander: &Expander{Expanded: true},
 		ScopeExpander:        &Expander{},
@@ -159,7 +161,8 @@ func (t *SongPanel) layoutSongOptions(gtx C) D {
 		return cpuLabel.Layout(gtx)
 	}
 
-	synthBtn := Btn(tr.Theme, &tr.Theme.Button.Text, t.SynthBtn, tr.Model.Play().SyntherName(), "")
+	synthBtn := Btn(tr.Theme, &tr.Theme.Button.Text, t.SynthBtn, tr.Model.Play().SyntherIndex().String(), "")
+	multithreadingBtn := ToggleIconBtn(tr.Play().Multithreading(), tr.Theme, t.MultithreadingBtn, icons.ToggleCheckBoxOutlineBlank, icons.ToggleCheckBox, "Threading disabled", "Threading enabled")
 
 	listItem := func(gtx C, index int) D {
 		switch index {
@@ -198,6 +201,7 @@ func (t *SongPanel) layoutSongOptions(gtx C) D {
 					return layout.Flex{Axis: layout.Vertical, Alignment: layout.End}.Layout(gtx,
 						layout.Rigid(func(gtx C) D { return layoutSongOptionRow(gtx, tr.Theme, "Load", cpuEnlargedWidget) }),
 						layout.Rigid(func(gtx C) D { return layoutSongOptionRow(gtx, tr.Theme, "Synth", synthBtn.Layout) }),
+						layout.Rigid(func(gtx C) D { return layoutSongOptionRow(gtx, tr.Theme, "Multithreading", multithreadingBtn.Layout) }),
 					)
 				},
 			)
diff --git a/tracker/instrument.go b/tracker/instrument.go
index e272378..c315950 100644
--- a/tracker/instrument.go
+++ b/tracker/instrument.go
@@ -237,7 +237,7 @@ func (m *InstrModel) warnAboutCrossThreadSends() {
 
 func (m *InstrModel) warnNoMultithreadSupport() {
 	for _, instr := range m.d.Song.Patch {
-		if instr.ThreadMaskM1 > 0 && !m.synthers[m.syntherIndex].SupportsMultithreading() {
+		if instr.ThreadMaskM1 > 0 && !m.curSynther.SupportsMultithreading() {
 			(*Alerts)(m).AddNamed("NoMultithreadSupport", "The current synth does not support multithreading and the patch was configured to use more than one thread", Warning)
 			return
 		}
diff --git a/tracker/model.go b/tracker/model.go
index 5b3593b..3605df3 100644
--- a/tracker/model.go
+++ b/tracker/model.go
@@ -82,8 +82,10 @@ type (
 		alerts []Alert
 		dialog Dialog
 
-		syntherIndex int              // the index of the synther used to create new synths
-		synthers     []sointu.Synther // the synther used to create new synths
+		syntherIndex   int              // the index of the synther used to create new synths
+		synthers       []sointu.Synther // the synther used to create new synths
+		multithreading bool             // is the multithreading enabled or not
+		curSynther     sointu.Synther   // the current synther, either multithreaded or not depending on multithreading
 
 		broker *Broker
 
@@ -197,6 +199,7 @@ func NewModel(broker *Broker, synthers []sointu.Synther, midiContext MIDIContext
 	m.derived.searchResults = make([]string, 0, len(sointu.UnitNames))
 	m.Unit().updateDerivedUnitSearch()
 	m.MIDI().Refresh().Do()
+	m.Play().setSynther(0, false)
 	go runDetector(broker)
 	go runSpecAnalyzer(broker)
 	return m
diff --git a/tracker/play.go b/tracker/play.go
index 45508a9..d2ae858 100644
--- a/tracker/play.go
+++ b/tracker/play.go
@@ -1,6 +1,9 @@
 package tracker
 
-import "github.com/vsariola/sointu"
+import (
+	"github.com/vsariola/sointu"
+	"github.com/vsariola/sointu/vm"
+)
 
 type Play Model
 
@@ -175,11 +178,7 @@ type playSyntherIndex Play
 func (v *playSyntherIndex) Value() int            { return v.syntherIndex }
 func (v *playSyntherIndex) Range() RangeInclusive { return RangeInclusive{0, len(v.synthers) - 1} }
 func (v *playSyntherIndex) SetValue(value int) bool {
-	if value < 0 || value >= len(v.synthers) {
-		return false
-	}
-	v.syntherIndex = value
-	TrySend(v.broker.ToPlayer, any(v.synthers[value]))
+	(*Play)(v).setSynther(value, v.multithreading)
 	return true
 }
 func (v *playSyntherIndex) StringOf(value int) string {
@@ -189,8 +188,26 @@ func (v *playSyntherIndex) StringOf(value int) string {
 	return v.synthers[value].Name()
 }
 
-// SyntherName returns the name of the currently selected synther.
-func (v *Play) SyntherName() string { return v.synthers[v.syntherIndex].Name() }
+func (m *Play) Multithreading() Bool { return MakeBool((*playMultithreading)(m)) }
+
+type playMultithreading Play
+
+func (v *playMultithreading) Value() bool         { return v.multithreading }
+func (v *playMultithreading) SetValue(value bool) { (*Play)(v).setSynther(v.syntherIndex, value) }
+
+func (m *Play) setSynther(index int, multithreading bool) {
+	if index < 0 || index >= len(m.synthers) {
+		return
+	}
+	m.syntherIndex = index
+	m.multithreading = multithreading
+	if multithreading {
+		m.curSynther = vm.MakeMultithreadSynther(m.synthers[m.syntherIndex])
+	} else {
+		m.curSynther = m.synthers[m.syntherIndex]
+	}
+	TrySend(m.broker.ToPlayer, any(m.curSynther))
+}
 
 // CPULoad fills the given buffer with CPU load information and returns the
 // number of threads filled.
diff --git a/tracker/song.go b/tracker/song.go
index af5fe5f..3239dee 100644
--- a/tracker/song.go
+++ b/tracker/song.go
@@ -346,7 +346,7 @@ func (m *SongModel) WriteWav(w io.WriteCloser, pcm16 bool) {
 		b := make([]byte, 32+2)
 		rand.Read(b)
 		name := fmt.Sprintf("%x", b)[2 : 32+2]
-		data, err := sointu.Play(m.synthers[m.syntherIndex], song, func(p float32) {
+		data, err := sointu.Play(m.curSynther, song, func(p float32) {
 			txt := fmt.Sprintf("Exporting song: %.0f%%", p*100)
 			TrySend(m.broker.ToModel, MsgToModel{Data: Alert{Message: txt, Priority: Info, Name: name, Duration: defaultAlertDuration}})
 		}) // render the song to calculate its length