diff --git a/assets/buzz.mp3 b/assets/buzz.mp3
new file mode 100644
index 0000000..1c0543e
Binary files /dev/null and b/assets/buzz.mp3 differ
diff --git a/src/lib/buzzer.rs b/src/lib/buzzer.rs
index b03f3f6..febe2d2 100644
--- a/src/lib/buzzer.rs
+++ b/src/lib/buzzer.rs
@@ -1,13 +1,11 @@
 use std::collections::HashSet;
-use std::f32::consts::TAU;
-use std::io::Cursor;
 use std::sync::Arc;
 
 use serenity::all::{
     ButtonStyle, ChannelId, CreateActionRow, CreateButton, GuildId, MessageId, UserId,
 };
 use serenity::prelude::TypeMapKey;
-use songbird::input::{Input, RawAdapter};
+use songbird::input::Input;
 use tokio::sync::Mutex;
 
 pub const BUZZER_CUSTOM_ID: &str = "buzzer:press";
@@ -87,33 +85,11 @@ fn control_components(is_open: bool, session_ended: bool) -> Vec<CreateActionRow
     vec![CreateActionRow::Buttons(vec![buzzer, reset, lock, unlock])]
 }
 
-/// Produces a short, self-contained buzzer tone as stereo f32 PCM.
+/// Returns the bundled buzzer sound.
 pub fn buzzer_sound() -> Input {
-    const SAMPLE_RATE: u32 = 48_000;
-    const DURATION_SECONDS: f32 = 0.4;
-    const FREQUENCY_HZ: f32 = 180.0;
+    const BUZZ_MP3: &[u8] = include_bytes!("../../assets/buzz.mp3");
 
-    let sample_count = (SAMPLE_RATE as f32 * DURATION_SECONDS) as usize;
-    let mut pcm = Vec::with_capacity(sample_count * 2 * size_of::<f32>());
-
-    for sample_index in 0..sample_count {
-        let time = sample_index as f32 / SAMPLE_RATE as f32;
-        let progress = sample_index as f32 / sample_count as f32;
-        let attack = (time / 0.01).min(1.0);
-        let release = ((1.0 - progress) / 0.08).min(1.0);
-        let envelope = attack * release;
-
-        // Odd harmonics give the tone the rasp of a physical game-show buzzer.
-        let phase = TAU * FREQUENCY_HZ * time;
-        let value =
-            envelope * (phase.sin() + (3.0 * phase).sin() / 3.0 + (5.0 * phase).sin() / 5.0) * 0.32;
-
-        for _ in 0..2 {
-            pcm.extend_from_slice(&value.to_le_bytes());
-        }
-    }
-
-    RawAdapter::new(Cursor::new(pcm), SAMPLE_RATE, 2).into()
+    BUZZ_MP3.into()
 }
 
 /// The application's single active buzzer session.
diff --git a/src/main.rs b/src/main.rs
index 2696f8b..f03dec2 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -83,6 +83,17 @@ impl EventHandler for Handler {
     async fn ready(&self, ctx: Context, ready: Ready) {
         println!("{} is connected!", ready.user.name);
 
+        // Commands were previously registered per guild. Clear those legacy
+        // registrations so only the global command set appears.
+        for guild in &ready.guilds {
+            if let Err(why) = guild.id.set_commands(&ctx.http, Vec::new()).await {
+                println!(
+                    "Cannot remove legacy slash commands from guild {}: {why}",
+                    guild.id
+                );
+            }
+        }
+
         let commands = vec![
             commands::start::register(),
             commands::reset::register(),