diff --git a/src/audio.rs b/src/audio.rs
index afa854d..8526266 100644
--- a/src/audio.rs
+++ b/src/audio.rs
@@ -1,110 +1,101 @@
-use crate::config::GameConfig;
-use crate::AppSet;
+//! Exposes a plugin that starts, stops, and modulates in-game audio when events are emitted
+use crate::assets::audio_assets::GameAudioAssets;
+use crate::components::audio::{ChangeBackgroundMusicEvent, PlaySoundEffectEvent};
 use bevy::prelude::*;
 use bevy_kira_audio::prelude::*;
-use std::time::Duration;
 
-const SPATIAL_AUDIO_MAX_DISTANCE: f32 = 400.0;
+/// Starts, stops, and modulates in-game audio when we receive a `PlaySoundEffectEvent` or `ChangeBackgroundMusicEvent`.
+pub(super) fn plugin(app: &mut App) {
+    app.add_event::<PlaySoundEffectEvent>();
+    app.add_event::<ChangeBackgroundMusicEvent>();
 
-pub fn play_sound_effects(
-    audio: &Res<Audio>,
-    config: &GameConfig,
-    source: Handle<AudioSource>,
-    position: &Option<Vec2>,
-    camera_position: Vec2,
-) {
-    let volume = match position {
-        None => 1.0,
-        Some(p) => {
-            1.0 - ((*p - camera_position).length() / SPATIAL_AUDIO_MAX_DISTANCE)
-                .clamp(0.0, 1.0)
-                .powf(2.0)
-        }
-    };
+    app.add_audio_channel::<BackgroundMusicAudioChannel>()
+        .add_audio_channel::<MenuAudioChannel>()
+        .add_audio_channel::<SoundEffectsAudioChannel>();
 
-    let panning = match position {
-        None => 0.5,
-        Some(p) => 0.5 + ((p.x - camera_position.x) / SPATIAL_AUDIO_MAX_DISTANCE).clamp(-0.5, 0.5),
-    };
+    app.add_systems(Startup, set_audio_volume_system);
 
-    audio
-        .play(source.clone())
-        .with_volume(Volume::Amplitude((config.sfx_volume * volume) as f64))
-        .with_panning(panning as f64)
-        .handle();
+    app.add_systems(
+        Update,
+        (play_sound_effect_system, change_bg_music_system)
+            .run_if(resource_exists::<GameAudioAssets>),
+    );
 }
 
-/// 表示下一个播放的BGM的资源
-#[derive(Resource, Default)]
-pub struct NextBgm(pub Option<Handle<AudioSource>>);
+// audio channels
+#[derive(Resource)]
+pub struct BackgroundMusicAudioChannel;
+#[derive(Resource)]
+pub struct MenuAudioChannel;
+#[derive(Resource)]
+pub struct SoundEffectsAudioChannel;
 
-struct SourceAndInstance {
-    instance: Handle<AudioInstance>,
-    source: Handle<AudioSource>,
+/// Sets the volume of the audio channels to "sane defaults"
+fn set_audio_volume_system(
+    background_audio_channel: Res<AudioChannel<BackgroundMusicAudioChannel>>,
+    menu_audio_channel: Res<AudioChannel<MenuAudioChannel>>,
+    effects_audio_channel: Res<AudioChannel<SoundEffectsAudioChannel>>,
+) {
+    background_audio_channel.set_volume(0.20);
+    menu_audio_channel.set_volume(0.05);
+    effects_audio_channel.set_volume(0.80);
 }
 
-#[derive(Resource, Default)]
-struct CurrentBGM(Option<SourceAndInstance>);
+/// Play sound effects when we receive events. This should be called every frame for snappy audio.
+fn play_sound_effect_system(
+    mut play_sound_event_reader: EventReader<PlaySoundEffectEvent>,
+    audio_channel: Res<AudioChannel<SoundEffectsAudioChannel>>,
+    audio_assets: Res<GameAudioAssets>,
+) {
+    for event in play_sound_event_reader.read() {
+        audio_channel.play(audio_assets.get_sound_effect(&event.sound_effect_type));
+    }
+}
 
-fn change_bgm(
-    mut current_bgm: ResMut<CurrentBGM>,
-    next_bgm: ResMut<NextBgm>,
-    audio: Res<Audio>,
-    mut audio_instances: ResMut<Assets<AudioInstance>>,
-    config: Res<GameConfig>,
+/// System to handle background music changes based on events.
+///
+/// This system listens for `ChangeBackgroundMusicEvent` events and updates
+/// the background music accordingly. It can stop the current music, start new
+/// music, handle looping, and apply fade-in and fade-out effects if specified in the event.
+///
+/// - If an event specifies a fade-out duration, the current track will fade out before stopping.
+/// - If a new background music type is provided, it will play the corresponding track from the `GameAudioAssets`.
+/// - The system supports looping the new track from a specified point and applying a fade-in effect if specified.
+///
+/// Parameters:
+/// - `EventReader<ChangeBackgroundMusicEvent>`: Reads events that dictate when and how to change background music.
+/// - `AudioChannel<BackgroundMusicAudioChannel>`: Controls the background music audio channel, allowing for stop, play, and fade effects.
+/// - `GameAudioAssets`: A resource that holds all available audio assets.
+fn change_bg_music_system(
+    mut change_bg_music_event_reader: EventReader<ChangeBackgroundMusicEvent>,
+    audio_channel: Res<AudioChannel<BackgroundMusicAudioChannel>>,
+    audio_assets: Res<GameAudioAssets>,
 ) {
-    let NextBgm(ref next_bgm_or_none) = *next_bgm;
+    for event in change_bg_music_event_reader.read() {
+        // stop audio if playing sound
+        if audio_channel.is_playing_sound() {
+            let mut stop_command = audio_channel.stop();
 
-    if let Some(ref mut current_handle) = &mut current_bgm.0 {
-        if let Some(ref next) = *next_bgm_or_none {
-            if current_handle.source.id() != next.id() {
-                if let Some(instance) = audio_instances.get_mut(&current_handle.instance) {
-                    instance.stop(AudioTween::new(Duration::from_secs(1), AudioEasing::Linear));
-                }
-                let instance = audio
-                    .play(next.clone())
-                    .with_volume(Volume::Amplitude(config.bgm_volume as f64))
-                    .looped()
-                    .handle();
-                current_bgm.0 = Some(SourceAndInstance {
-                    instance: instance.clone(),
-                    source: next.clone(),
-                });
+            // use fade if specified
+            if let Some(fade_out) = event.fade_out {
+                stop_command.fade_out(AudioTween::new(fade_out, AudioEasing::Linear));
             }
         }
-    } else if let Some(ref next) = *next_bgm_or_none {
-        let instance = audio
-            .play(next.clone())
-            .with_volume(Volume::Amplitude(config.bgm_volume as f64))
-            .looped()
-            .handle();
-        current_bgm.0 = Some(SourceAndInstance {
-            instance: instance.clone(),
-            source: next.clone(),
-        });
-    }
-}
+        // info!("play_sound_effect_system: change_bg_music_event");
+        // play music if provided a type
+        if let Some(bg_music_type) = event.bg_music_type.clone() {
+            let mut start_command =
+                audio_channel.play(audio_assets.get_bg_music_asset(&bg_music_type));
 
-fn update_bgm_volume(
-    mut current_bgm: ResMut<CurrentBGM>,
-    mut audio_instances: ResMut<Assets<AudioInstance>>,
-    config: Res<GameConfig>,
-) {
-    if config.is_changed() {
-        if let Some(ref mut current_handle) = &mut current_bgm.0 {
-            if let Some(instance) = audio_instances.get_mut(&current_handle.instance) {
-                instance.set_volume(
-                    Volume::Amplitude(config.bgm_volume as f64),
-                    AudioTween::linear(Duration::from_millis(100)),
-                );
+            // loop if true
+            if let Some(loop_from) = event.loop_from {
+                start_command.loop_from(loop_from);
+            }
+
+            // use fade if specified
+            if let Some(fade_in) = event.fade_in {
+                start_command.fade_in(AudioTween::new(fade_in, AudioEasing::Linear));
             }
         }
     }
 }
-
-pub(super) fn plugin(app: &mut App) {
-    app.add_systems(FixedUpdate, change_bgm.before(AppSet::RecordInput));
-    app.add_systems(Update, update_bgm_volume);
-    app.init_resource::<NextBgm>();
-    app.init_resource::<CurrentBGM>();
-}
diff --git a/src/gameplay/player.rs b/src/gameplay/player.rs
index a937b35..20383d3 100644
--- a/src/gameplay/player.rs
+++ b/src/gameplay/player.rs
@@ -1,7 +1,6 @@
 use crate::assets::player_assets::PlayerAssets;
 use crate::components::character::CharacterType;
-use crate::components::input::{InputsResource, MainMenuExplorer, MenuAction, PlayerAction};
-use crate::components::player::{PlayerInput, PlayersResource};
+use crate::components::input::{InputsResource, PlayerAction};
 use crate::{
     components::health::{FighterBundle, HealthComponent},
     gameplay::{
@@ -15,7 +14,6 @@ use crate::{
     util::RenderLayer,
     AppSet, CameraShake, MainCamera,
 };
-use bevy::input::gamepad::GamepadButtonChangedEvent;
 use bevy::input::mouse::MouseWheel;
 use bevy::window::WindowMode;
 use bevy::{
diff --git a/src/screens/credits.rs b/src/screens/credits.rs
index 77214c0..8d962d3 100644
--- a/src/screens/credits.rs
+++ b/src/screens/credits.rs
@@ -1,18 +1,20 @@
 //! A credits screen that can be accessed from the title screen.
 use bevy::prelude::*;
+use std::time::Duration;
 
-use crate::assets::audio_assets::{Fonts, Music};
-use crate::audio::NextBgm;
+use crate::assets::audio_assets::Fonts;
+use crate::components::audio::{BGMusicType, ChangeBackgroundMusicEvent};
 use crate::{screens::AppStates, theme::prelude::*};
 
 pub(super) fn plugin(app: &mut App) {
     app.add_systems(OnEnter(AppStates::Credits), spawn_credits_screen);
-
-    app.add_systems(OnEnter(AppStates::Credits), play_credits_music);
-    app.add_systems(OnExit(AppStates::Credits), stop_music);
 }
 
-fn spawn_credits_screen(mut commands: Commands, fonts: Res<Fonts>) {
+fn spawn_credits_screen(
+    mut commands: Commands,
+    fonts: Res<Fonts>,
+    mut change_bg_music_event_writer: EventWriter<ChangeBackgroundMusicEvent>,
+) {
     commands
         .ui_root()
         .insert(StateScoped(AppStates::Credits))
@@ -27,16 +29,23 @@ fn spawn_credits_screen(mut commands: Commands, fonts: Res<Fonts>) {
                 .button("Back", fonts.primary.clone())
                 .observe(enter_title_screen);
         });
+    change_bg_music_event_writer.send(ChangeBackgroundMusicEvent {
+        bg_music_type: Some(BGMusicType::Game),
+        loop_from: Some(0.0),
+        fade_in: Some(Duration::from_secs(2)),
+        fade_out: Some(Duration::from_secs(2)),
+    });
 }
 
-fn enter_title_screen(_trigger: Trigger<OnPress>, mut next_screen: ResMut<NextState<AppStates>>) {
+fn enter_title_screen(
+    _trigger: Trigger<OnPress>,
+    mut next_screen: ResMut<NextState<AppStates>>,
+    mut change_bg_music_event_writer: EventWriter<ChangeBackgroundMusicEvent>,
+) {
+    // fade music out
+    change_bg_music_event_writer.send(ChangeBackgroundMusicEvent {
+        fade_out: Some(Duration::from_secs(1)),
+        ..default()
+    });
     next_screen.set(AppStates::MainMenu);
 }
-
-fn play_credits_music(mut next_bgm: ResMut<NextBgm>, music: Res<Music>) {
-    *next_bgm = NextBgm(Some(music.monkeys.clone()));
-}
-
-fn stop_music(mut next_bgm: ResMut<NextBgm>) {
-    *next_bgm = NextBgm(None);
-}
diff --git a/src/screens/gameplay.rs b/src/screens/gameplay.rs
index 68c36dd..dbf678e 100644
--- a/src/screens/gameplay.rs
+++ b/src/screens/gameplay.rs
@@ -1,7 +1,6 @@
 //! The screen state for the main gameplay.
-
-use crate::assets::audio_assets::{Fonts, Music};
-use crate::audio::NextBgm;
+use crate::assets::audio_assets::Fonts;
+use crate::components::audio::{BGMusicType, ChangeBackgroundMusicEvent};
 use crate::gameplay::level::spawn_level as spawn_level_command;
 use crate::gameplay::loot::Points;
 use crate::gameplay::GameStates;
@@ -9,11 +8,10 @@ use crate::theme::interaction::OnPress;
 use crate::{screens::AppStates, theme::prelude::*};
 use bevy::input::common_conditions::input_just_pressed;
 use bevy::prelude::*;
+use std::time::Duration;
 
 pub(super) fn plugin(app: &mut App) {
     app.add_systems(OnEnter(AppStates::Game), spawn_level);
-    app.add_systems(OnEnter(AppStates::Game), play_gameplay_music);
-    app.add_systems(OnExit(AppStates::Game), stop_music);
     app.add_systems(OnEnter(GameStates::GameOver), setup_game_over);
     app.add_systems(
         Update,
@@ -22,19 +20,28 @@ pub(super) fn plugin(app: &mut App) {
     );
 }
 
-fn spawn_level(mut commands: Commands) {
+fn spawn_level(
+    mut commands: Commands,
+    mut change_bg_music_event_writer: EventWriter<ChangeBackgroundMusicEvent>,
+) {
+    change_bg_music_event_writer.send(ChangeBackgroundMusicEvent {
+        bg_music_type: Some(BGMusicType::Game),
+        loop_from: Some(0.0),
+        fade_in: Some(Duration::from_secs(2)),
+        fade_out: Some(Duration::from_secs(2)),
+    });
     commands.add(spawn_level_command);
 }
 
-fn play_gameplay_music(mut next_bgm: ResMut<NextBgm>, music: Res<Music>) {
-    *next_bgm = NextBgm(Some(music.gameplay.clone()));
-}
-
-fn stop_music(mut next_bgm: ResMut<NextBgm>) {
-    *next_bgm = NextBgm(None);
-}
-
-fn return_to_title_screen(mut next_screen: ResMut<NextState<AppStates>>) {
+fn return_to_title_screen(
+    mut next_screen: ResMut<NextState<AppStates>>,
+    mut change_bg_music_event_writer: EventWriter<ChangeBackgroundMusicEvent>,
+) {
+    // fade music out
+    change_bg_music_event_writer.send(ChangeBackgroundMusicEvent {
+        fade_out: Some(Duration::from_secs(2)),
+        ..default()
+    });
     next_screen.set(AppStates::MainMenu);
 }
 
diff --git a/src/screens/title.rs b/src/screens/title.rs
index a2cde28..47fb68d 100644
--- a/src/screens/title.rs
+++ b/src/screens/title.rs
@@ -1,7 +1,7 @@
 //! The title screen that appears when the game starts.
 
-use crate::assets::audio_assets::{Fonts, Music};
-use crate::audio::NextBgm;
+use crate::assets::audio_assets::Fonts;
+use crate::components::audio::{BGMusicType, ChangeBackgroundMusicEvent};
 use crate::components::character::CharacterType;
 use crate::components::events::{ButtonActionEvent, PlayerJoinEvent};
 use crate::components::input::{
@@ -14,24 +14,24 @@ use bevy::input::gamepad::GamepadButtonChangedEvent;
 use bevy::prelude::*;
 use bevy::window::WindowMode;
 use leafwing_input_manager::action_state::ActionState;
+use std::time::Duration;
 
 pub(super) fn plugin(app: &mut App) {
     app.add_event::<PlayerJoinEvent>();
     app.add_event::<ButtonActionEvent>();
-    app.add_systems(OnEnter(AppStates::MainMenu), spawn_title_screen);
-    app.add_systems(OnEnter(AppStates::MainMenu), play_title_music);
-    app.add_systems(OnExit(AppStates::MainMenu), stop_title_music);
+    app.add_systems(OnEnter(AppStates::MainMenu), setup_title_screen);
     app.add_systems(
         Update,
         (player_join_system,).run_if(in_state(AppStates::MainMenu)),
     );
 }
 
-fn spawn_title_screen(
+fn setup_title_screen(
     mut commands: Commands,
     mut localize: ResMut<Localize>,
     config: Res<GameConfig>,
     fonts: Res<Fonts>,
+    mut change_bg_music_event_writer: EventWriter<ChangeBackgroundMusicEvent>,
 ) {
     localize.set_language(config.language.clone());
     commands
@@ -55,6 +55,13 @@ fn spawn_title_screen(
                 .button("Exit", fonts.primary.clone())
                 .observe(exit_app);
         });
+    // change music
+    change_bg_music_event_writer.send(ChangeBackgroundMusicEvent {
+        bg_music_type: Some(BGMusicType::Main),
+        loop_from: Some(0.0),
+        fade_in: Some(Duration::from_secs(2)),
+        fade_out: Some(Duration::from_secs(2)),
+    });
 }
 
 fn enter_gameplay_screen(
@@ -90,14 +97,6 @@ fn exit_app(_trigger: Trigger<OnPress>, mut app_exit: EventWriter<AppExit>) {
     app_exit.send(AppExit::Success);
 }
 
-fn play_title_music(mut next_bgm: ResMut<NextBgm>, music: Res<Music>) {
-    *next_bgm = NextBgm(Some(music.title.clone()));
-}
-
-fn stop_title_music(mut next_bgm: ResMut<NextBgm>) {
-    *next_bgm = NextBgm(None);
-}
-
 fn toggle_fullscreen(_trigger: Trigger<OnPress>, mut window_query: Query<&mut Window>) {
     let mut window = window_query.single_mut();
     window.mode = match window.mode {