Background Music with music.play

By the end of this lesson you can:

• Place a music file in the music/ folder and loop it with music.play("track").
• Adjust playback volume with music.set_volume() and mute/unmute on a key press.
• Fade the music out smoothly with music.fadeout(seconds) when the game ends.

Last lesson you played one-shot sound effects with sounds.name.play(). What does this snippet do? Predict before reading on:

def on_mouse_down(pos, button):
    if score_rect.collidepoint(pos):
        sounds.chime.play()
    else:
        sounds.thud.play()

Think of music as a CD player built into Pygame Zero. You press play once — it loops forever on its own. You turn the volume knob. You press stop or fade. That is all there is to it.

Folder layout

Music files live in a music/ folder next to your Python file:

my_game/
├── mygame.py
└── music/
    ├── theme.ogg
    └── gameover.ogg

Pygame Zero supports .ogg and .mp3 for music (unlike sounds, MP3 works here). Use .ogg when possible — it is smaller and plays reliably everywhere.

Starting and stopping

# Start looping the theme track immediately
music.play("theme")

# Stop it instantly
music.stop()

# Fade out over 3 seconds (nice for game-over screens)
music.fadeout(3)

Pass the filename without the extension. "theme" plays music/theme.ogg (or music/theme.mp3).

Volume control

# 0.0 = silent, 1.0 = full volume
music.set_volume(0.4)   # comfortable background level

Call set_volume any time — inside update(), in an event hook, or at the start of the file. Volume persists until you change it again.

Mei Ling wants background music that the player can toggle on and off by pressing M. Save as music_demo.py:

# music_demo.py — looping music with mute toggle
import pgzrun

WIDTH = 480
HEIGHT = 300
TITLE = "Music Demo"

is_muted = False

def on_key_down(key):
    global is_muted
    if key == keys.M:
        is_muted = not is_muted
        if is_muted:
            music.set_volume(0.0)
        else:
            music.set_volume(0.5)

def draw():
    screen.fill("midnightblue")
    label = "Music: OFF (press M)" if is_muted else "Music: ON  (press M)"
    screen.draw.text(label, center=(240, 150), fontsize=28, color="white")

music.play("theme")        # music/theme.ogg loops automatically
music.set_volume(0.5)
pgzrun.go()

The global keyword lets the key handler write to is_muted which lives outside the function. The label updates each frame so the player always knows the current state.

Place an .ogg or .mp3 file in the music/ folder. Call music.play("filename") once — Pygame Zero loops it forever. Use music.set_volume(0.0–1.0) to adjust loudness, andmusic.fadeout(seconds) for a smooth ending. Only one track plays at a time.