diff --git a/backend/mpris.go b/backend/mpris.go
index 084a295..39bd08c 100644
--- a/backend/mpris.go
+++ b/backend/mpris.go
@@ -207,12 +207,12 @@ func (m *MPRISHandler) PlaybackStatus() (types.PlaybackStatus, error) {
 }
 
 func (m *MPRISHandler) LoopStatus() (types.LoopStatus, error) {
-	switch m.pm.LoopMode() {
-	case LoopModeAll:
+	switch m.pm.GetLoopMode() {
+	case player.LoopAll:
 		return types.LoopStatusPlaylist, nil
-	case LoopModeOne:
+	case player.LoopOne:
 		return types.LoopStatusTrack, nil
-	case LoopModeNone:
+	case player.LoopNone:
 		return types.LoopStatusNone, nil
 	}
 	return "", errors.New("unknown loop status")
@@ -221,11 +221,11 @@ func (m *MPRISHandler) LoopStatus() (types.LoopStatus, error) {
 func (m *MPRISHandler) SetLoopStatus(status types.LoopStatus) error {
 	switch status {
 	case types.LoopStatusPlaylist:
-		return m.pm.SetLoopMode(LoopModeAll)
+		return m.pm.SetLoopMode(player.LoopAll)
 	case types.LoopStatusTrack:
-		return m.pm.SetLoopMode(LoopModeOne)
+		return m.pm.SetLoopMode(player.LoopOne)
 	case types.LoopStatusNone:
-		return m.pm.SetLoopMode(LoopModeNone)
+		return m.pm.SetLoopMode(player.LoopNone)
 	}
 	return errors.New("unknown loop status")
 }
diff --git a/backend/playbackmanager.go b/backend/playbackmanager.go
index d9a7d9e..8e6d1a8 100644
--- a/backend/playbackmanager.go
+++ b/backend/playbackmanager.go
@@ -2,14 +2,12 @@ package backend
 
 import (
 	"context"
-	"fmt"
 	"log"
 	"time"
 
 	"github.com/dweymouth/supersonic/backend/mediaprovider"
 	"github.com/dweymouth/supersonic/backend/util"
 	"github.com/dweymouth/supersonic/player"
-	"github.com/dweymouth/supersonic/player/mpv"
 	"github.com/dweymouth/supersonic/sharedutil"
 )
 
@@ -20,14 +18,6 @@ var (
 	ReplayGainAuto  = "Auto"
 )
 
-type LoopMode int
-
-const (
-	LoopModeNone LoopMode = LoopMode(player.LoopNone)
-	LoopModeAll  LoopMode = LoopMode(player.LoopAll)
-	LoopModeOne  LoopMode = LoopMode(player.LoopOne)
-)
-
 // A high-level Subsonic-aware playback backend.
 // Manages loading tracks into the Player queue,
 // sending callbacks on play time updates and track changes.
@@ -36,7 +26,7 @@ type PlaybackManager struct {
 	cancelPollPos context.CancelFunc
 	pollingTick   *time.Ticker
 	sm            *ServerManager
-	player        *mpv.Player
+	player        player.BasePlayer
 
 	playTimeStopwatch   util.Stopwatch
 	curTrackTime        float64
@@ -44,7 +34,7 @@ type PlaybackManager struct {
 	callbacksDisabled   bool
 
 	playQueue     []*mediaprovider.Track
-	nowPlayingIdx int64
+	nowPlayingIdx int
 
 	// to pass to onSongChange listeners; clear once listeners have been called
 	lastScrobbled *mediaprovider.Track
@@ -55,7 +45,7 @@ type PlaybackManager struct {
 	// registered callbacks
 	onSongChange     []func(nowPlaying, justScrobbledIfAny *mediaprovider.Track)
 	onPlayTimeUpdate []func(float64, float64)
-	onLoopModeChange []func(LoopMode)
+	onLoopModeChange []func(player.LoopMode)
 	onVolumeChange   []func(int)
 	onSeek           []func()
 	onPaused         []func()
@@ -66,7 +56,7 @@ type PlaybackManager struct {
 func NewPlaybackManager(
 	ctx context.Context,
 	s *ServerManager,
-	p *mpv.Player,
+	p player.BasePlayer,
 	scrobbleCfg *ScrobbleConfig,
 	transcodeCfg *TranscodingConfig,
 ) *PlaybackManager {
@@ -79,8 +69,8 @@ func NewPlaybackManager(
 		scrobbleCfg:  scrobbleCfg,
 		transcodeCfg: transcodeCfg,
 	}
-	p.OnTrackChange(func(tracknum int64) {
-		if tracknum >= int64(len(pm.playQueue)) {
+	p.OnTrackChange(func(tracknum int) {
+		if tracknum >= len(pm.playQueue) {
 			return
 		}
 		pm.checkScrobble() // scrobble the previous song if needed
@@ -165,7 +155,7 @@ func (p *PlaybackManager) OnPlayTimeUpdate(cb func(float64, float64)) {
 }
 
 // Registers a callback that is notified whenever the loop mode changes.
-func (p *PlaybackManager) OnLoopModeChange(cb func(LoopMode)) {
+func (p *PlaybackManager) OnLoopModeChange(cb func(player.LoopMode)) {
 	p.onLoopModeChange = append(p.onLoopModeChange, cb)
 }
 
@@ -223,11 +213,18 @@ func (p *PlaybackManager) LoadTracks(tracks []*mediaprovider.Track, appendToQueu
 		util.ShuffleSlice(nums)
 	}
 	for _, i := range nums {
-		url, err := p.sm.Server.GetStreamURL(tracks[i].ID, p.transcodeCfg.ForceRawFile)
-		if err != nil {
-			return err
+
+		if urlP, ok := p.player.(player.URLPlayer); ok {
+			url, err := p.sm.Server.GetStreamURL(tracks[i].ID, p.transcodeCfg.ForceRawFile)
+			if err != nil {
+				return err
+			}
+			urlP.AppendFile(url)
+		} else if trP, ok := p.player.(player.TrackIDPlayer); ok {
+			trP.AppendTrack(tracks[i].ID)
+		} else {
+			panic("unsupported player type")
 		}
-		p.player.AppendFile(url)
 		// ensure a deep copy of the track info so that we can maintain our own state
 		// (tracking play count increases, favorite, and rating) without messing up
 		// other views' track models
@@ -245,7 +242,7 @@ func (p *PlaybackManager) PlayAlbum(albumID string, firstTrack int, shuffle bool
 		p.SetReplayGainMode(player.ReplayGainAlbum)
 	}
 	if firstTrack <= 0 {
-		return p.player.PlayFromBeginning()
+		return p.player.PlayTrackAt(0)
 	}
 	return p.player.PlayTrackAt(firstTrack)
 }
@@ -258,7 +255,7 @@ func (p *PlaybackManager) PlayPlaylist(playlistID string, firstTrack int, shuffl
 		p.SetReplayGainMode(player.ReplayGainTrack)
 	}
 	if firstTrack <= 0 {
-		return p.player.PlayFromBeginning()
+		return p.player.PlayTrackAt(0)
 	}
 	return p.player.PlayTrackAt(firstTrack)
 }
@@ -276,7 +273,7 @@ func (p *PlaybackManager) PlayTrack(trackID string) error {
 }
 
 func (p *PlaybackManager) PlayFromBeginning() error {
-	return p.player.PlayFromBeginning()
+	return p.player.PlayTrackAt(0)
 }
 
 func (p *PlaybackManager) PlayTrackAt(idx int) error {
@@ -374,6 +371,12 @@ func (p *PlaybackManager) StopAndClearPlayQueue() {
 }
 
 func (p *PlaybackManager) SetReplayGainOptions(config ReplayGainConfig) {
+	rGainPlayer, ok := p.player.(player.ReplayGainPlayer)
+	if !ok {
+		log.Println("Error: player doesn't support ReplayGain")
+		return
+	}
+
 	p.replayGainCfg = config
 	mode := player.ReplayGainNone
 	switch config.Mode {
@@ -388,7 +391,7 @@ func (p *PlaybackManager) SetReplayGainOptions(config ReplayGainConfig) {
 	if config.Mode == ReplayGainAuto {
 		mode = player.ReplayGainTrack
 	}
-	p.player.SetReplayGainOptions(player.ReplayGainOptions{
+	rGainPlayer.SetReplayGainOptions(player.ReplayGainOptions{
 		Mode:            mode,
 		PreventClipping: config.PreventClipping,
 		PreampGain:      config.PreampGainDB,
@@ -396,7 +399,12 @@ func (p *PlaybackManager) SetReplayGainOptions(config ReplayGainConfig) {
 }
 
 func (p *PlaybackManager) SetReplayGainMode(mode player.ReplayGainMode) {
-	p.player.SetReplayGainOptions(player.ReplayGainOptions{
+	rGainPlayer, ok := p.player.(player.ReplayGainPlayer)
+	if !ok {
+		log.Println("Error: player doesn't support ReplayGain")
+		return
+	}
+	rGainPlayer.SetReplayGainOptions(player.ReplayGainOptions{
 		PreventClipping: p.replayGainCfg.PreventClipping,
 		PreampGain:      p.replayGainCfg.PreampGainDB,
 		Mode:            mode,
@@ -406,18 +414,29 @@ func (p *PlaybackManager) SetReplayGainMode(mode player.ReplayGainMode) {
 // Changes the loop mode of the player to the next one.
 // Useful for toggling UI elements, to change modes without knowing the current player mode.
 func (p *PlaybackManager) SetNextLoopMode() error {
-	if err := p.player.SetNextLoopMode(); err != nil {
-		return err
+	var err error
+	switch p.GetLoopMode() {
+	case player.LoopNone:
+		err = p.SetLoopMode(player.LoopAll)
+	case player.LoopAll:
+		err = p.SetLoopMode(player.LoopOne)
+	case player.LoopOne:
+		err = p.SetLoopMode(player.LoopNone)
+	default:
+		return nil
 	}
 
+	if err != nil {
+		return err
+	}
 	for _, cb := range p.onLoopModeChange {
-		cb(LoopMode(p.player.GetLoopMode()))
+		cb(p.player.GetLoopMode())
 	}
 
 	return nil
 }
 
-func (p *PlaybackManager) SetLoopMode(loopMode LoopMode) error {
+func (p *PlaybackManager) SetLoopMode(loopMode player.LoopMode) error {
 	if err := p.player.SetLoopMode(player.LoopMode(loopMode)); err != nil {
 		return err
 	}
@@ -429,8 +448,8 @@ func (p *PlaybackManager) SetLoopMode(loopMode LoopMode) error {
 	return nil
 }
 
-func (p *PlaybackManager) LoopMode() LoopMode {
-	return LoopMode(p.player.GetLoopMode())
+func (p *PlaybackManager) GetLoopMode() player.LoopMode {
+	return p.player.GetLoopMode()
 }
 
 func (p *PlaybackManager) PlayerStatus() player.Status {
@@ -457,12 +476,15 @@ func (p *PlaybackManager) SeekNext() error {
 }
 
 func (p *PlaybackManager) SeekBackOrPrevious() error {
-	return p.player.SeekBackOrPrevious()
+	if p.player.GetStatus().TimePos > 3 {
+		return p.player.SeekSeconds(0)
+	}
+	return p.player.SeekPrevious()
 }
 
 // Seek to given absolute position in the current track by seconds.
 func (p *PlaybackManager) SeekSeconds(sec float64) error {
-	return p.player.Seek(fmt.Sprintf("%0.2f", sec), mpv.SeekAbsolute)
+	return p.player.SeekSeconds(sec)
 }
 
 // Seek to a fractional position in the current track [0..1]
@@ -472,7 +494,8 @@ func (p *PlaybackManager) SeekFraction(fraction float64) error {
 	} else if fraction > 1 {
 		fraction = 1
 	}
-	return p.player.Seek(fmt.Sprintf("%0.1f", fraction*100), mpv.SeekAbsolutePercent)
+	target := p.curTrackTime * fraction
+	return p.player.SeekSeconds(target)
 }
 
 func (p *PlaybackManager) Stop() error {
diff --git a/player/mpv/player.go b/player/mpv/player.go
index 7775906..0703976 100644
--- a/player/mpv/player.go
+++ b/player/mpv/player.go
@@ -15,16 +15,6 @@ import (
 // Error returned by many Player functions if called before the player has not been initialized.
 var ErrUnitialized error = errors.New("mpv player uninitialized")
 
-// Argument to Seek function (SeekAbsolute, SeekRelative, SeekAbsolutePercent, SeekRelativePercent).
-type SeekMode int
-
-const (
-	SeekAbsolute SeekMode = iota
-	SeekRelative
-	SeekAbsolutePercent
-	SeekRelativePercent
-)
-
 // Information about a specific audio device.
 // Returned by ListAudioDevices.
 type AudioDevice struct {
@@ -56,6 +46,8 @@ type MediaInfo struct {
 	Bitrate int
 }
 
+var _ player.URLPlayer = (*Player)(nil)
+
 // Player encapsulates the mpv instance and provides functions
 // to control it and to check its status.
 type Player struct {
@@ -80,7 +72,7 @@ type Player struct {
 	onStopped     []func()
 	onPlaying     []func()
 	onSeek        []func()
-	onTrackChange []func(int64)
+	onTrackChange []func(int)
 }
 
 // Returns a new player.
@@ -203,30 +195,25 @@ func (p *Player) ClearPlayQueue() error {
 
 // Seeks within the currently playing track.
 // See MPV seek command documentation for more details.
-func (p *Player) Seek(target string, mode SeekMode) error {
+func (p *Player) SeekSeconds(secs float64) error {
 	if !p.initialized {
 		return ErrUnitialized
 	}
+	target := fmt.Sprintf("%0.1f", secs)
 	p.seeking = true
-	err := p.mpv.Command([]string{"seek", target, mode.String()})
+	err := p.mpv.Command([]string{"seek", target, "absolute"})
 	return err
 }
 
-// Seeks to the beginning of the current track if:
-//   - The current track is the first track in the play queue, or
-//   - The current time is more than 3 seconds past the beginning of the track.
-//
-// Else seeks to the beginning of the previous track.
-func (p *Player) SeekBackOrPrevious() error {
+// Seeks to the beginning of the previous track,
+// or if no previous track, seeks to the beginning of the current track.
+func (p *Player) SeekPrevious() error {
 	if !p.initialized {
 		return ErrUnitialized
 	}
 
-	if pos, err := p.getInt64Property("time-pos"); err == nil && pos > 3 {
-		return p.Seek("0", SeekAbsolutePercent)
-	}
 	if pos, err := p.getInt64Property("playlist-pos"); err == nil && pos == 0 {
-		return p.Seek("0", SeekAbsolutePercent)
+		return p.SeekSeconds(0)
 	}
 	return p.mpv.Command([]string{"playlist-prev"})
 }
@@ -445,21 +432,6 @@ func (p *Player) SetLoopMode(mode player.LoopMode) error {
 	return nil
 }
 
-// Change the loop mode of the player to the next one.
-// Useful for toggling UI elements, to change modes without knowing the current player mode.
-func (p *Player) SetNextLoopMode() error {
-	switch p.loopMode {
-	case player.LoopNone:
-		return p.SetLoopMode(player.LoopAll)
-	case player.LoopAll:
-		return p.SetLoopMode(player.LoopOne)
-	case player.LoopOne:
-		return p.SetLoopMode(player.LoopNone)
-	default:
-		return nil
-	}
-}
-
 // Get the current status of the player.
 func (p *Player) GetStatus() player.Status {
 	if !p.initialized {
@@ -475,7 +447,7 @@ func (p *Player) GetStatus() player.Status {
 		p.status.Duration = dur.(float64)
 	}
 	if playpos, err := p.getInt64Property("playlist-pos"); err == nil {
-		p.status.PlaylistPos = playpos
+		p.status.PlaylistPos = int(playpos)
 	}
 	return p.status
 }
@@ -586,7 +558,7 @@ func (p *Player) OnSeek(cb func()) {
 // Registers a callback which is invoked when the currently playing track changes,
 // or when playback begins at any time from the Stopped state.
 // Callback is invoked with the index of the currently playing track (zero-based).
-func (p *Player) OnTrackChange(cb func(int64)) {
+func (p *Player) OnTrackChange(cb func(int)) {
 	p.onTrackChange = append(p.onTrackChange, cb)
 }
 
@@ -657,7 +629,7 @@ func (p *Player) eventHandler(ctx context.Context) {
 				if pos, err := p.getInt64Property("playlist-pos"); err == nil {
 					p.curPlaylistPos = pos
 					for _, cb := range p.onTrackChange {
-						cb(pos)
+						cb(int(pos))
 					}
 				}
 			case mpv.EVENT_IDLE:
@@ -668,17 +640,3 @@ func (p *Player) eventHandler(ctx context.Context) {
 		}
 	}
 }
-
-func (s SeekMode) String() string {
-	switch s {
-	case SeekAbsolute:
-		return "absolute"
-	case SeekRelative:
-		return "relative"
-	case SeekAbsolutePercent:
-		return "absolute-percent"
-	case SeekRelativePercent:
-		return "relative-percent"
-	}
-	return "UNKNOWN_SEEK_MODE"
-}
diff --git a/player/player.go b/player/player.go
index f7594c7..a33a2eb 100644
--- a/player/player.go
+++ b/player/player.go
@@ -1,5 +1,52 @@
 package player
 
+type URLPlayer interface {
+	BasePlayer
+	AppendFile(url string) error
+	PlayFile(url string) error
+}
+
+type TrackIDPlayer interface {
+	BasePlayer
+	AppendTrack(trackID string) error
+	PlayTrack(trackID string) error
+}
+
+type BasePlayer interface {
+	// Transport
+	PlayTrackAt(idx int) error
+	Continue() error
+	Pause() error
+	PlayPause() error
+	Stop() error
+	SeekPrevious() error
+	SeekNext() error
+	SeekSeconds(secs float64) error
+	IsSeeking() bool
+
+	SetVolume(int) error
+	GetVolume() int
+
+	GetStatus() Status
+
+	ClearPlayQueue() error
+	RemoveTrackAt(idx int) error
+
+	SetLoopMode(LoopMode) error
+	GetLoopMode() LoopMode
+
+	// Event API
+	OnPaused(func())
+	OnStopped(func())
+	OnPlaying(func())
+	OnSeek(func())
+	OnTrackChange(func(int))
+}
+
+type ReplayGainPlayer interface {
+	SetReplayGainOptions(ReplayGainOptions) error
+}
+
 // The playback state (Stopped, Paused, or Playing).
 type State int
 
@@ -15,7 +62,7 @@ type Status struct {
 	State       State
 	TimePos     float64
 	Duration    float64
-	PlaylistPos int64
+	PlaylistPos int
 }
 
 // The playback loop mode (LoopNone, LoopAll, LoopOne).
diff --git a/ui/mainwindow.go b/ui/mainwindow.go
index a410d86..32af290 100644
--- a/ui/mainwindow.go
+++ b/ui/mainwindow.go
@@ -162,13 +162,13 @@ func (m *MainWindow) SetupSystemTrayMenu(appName string, fyneApp fyne.App) {
 	if desk, ok := fyneApp.(desktop.App); ok {
 		menu := fyne.NewMenu(appName,
 			fyne.NewMenuItem("Play/Pause", func() {
-				_ = m.App.Player.PlayPause()
+				_ = m.App.PlaybackManager.PlayPause()
 			}),
 			fyne.NewMenuItem("Previous", func() {
-				_ = m.App.Player.SeekBackOrPrevious()
+				_ = m.App.PlaybackManager.SeekBackOrPrevious()
 			}),
 			fyne.NewMenuItem("Next", func() {
-				_ = m.App.Player.SeekNext()
+				_ = m.App.PlaybackManager.SeekNext()
 			}),
 			fyne.NewMenuItemSeparator(),
 			fyne.NewMenuItem("Volume +10%", func() {
@@ -298,7 +298,7 @@ func (m *MainWindow) addShortcuts() {
 		case fyne.KeyEscape:
 			m.Controller.CloseEscapablePopUp()
 		case fyne.KeySpace:
-			m.App.Player.PlayPause()
+			m.App.PlaybackManager.PlayPause()
 		}
 	})
 }
diff --git a/ui/widgets/auxcontrols.go b/ui/widgets/auxcontrols.go
index 518a7d1..88102da 100644
--- a/ui/widgets/auxcontrols.go
+++ b/ui/widgets/auxcontrols.go
@@ -7,7 +7,7 @@ import (
 	"fyne.io/fyne/v2/theme"
 	"fyne.io/fyne/v2/widget"
 
-	"github.com/dweymouth/supersonic/backend"
+	"github.com/dweymouth/supersonic/player"
 	myTheme "github.com/dweymouth/supersonic/ui/theme"
 	"github.com/dweymouth/supersonic/ui/util"
 )
@@ -67,15 +67,15 @@ func (a *AuxControls) OnChangeLoopMode(f func()) {
 	a.loop.OnTapped = f
 }
 
-func (a *AuxControls) SetLoopMode(mode backend.LoopMode) {
+func (a *AuxControls) SetLoopMode(mode player.LoopMode) {
 	switch mode {
-	case backend.LoopModeAll:
+	case player.LoopAll:
 		a.loop.Importance = widget.HighImportance
 		a.loop.Icon = myTheme.RepeatIcon
-	case backend.LoopModeOne:
+	case player.LoopOne:
 		a.loop.Importance = widget.HighImportance
 		a.loop.Icon = myTheme.RepeatOneIcon
-	case backend.LoopModeNone:
+	case player.LoopNone:
 		a.loop.Importance = widget.MediumImportance
 		a.loop.Icon = myTheme.RepeatIcon
 	}