What Background Music brings to your live shows

Background Music sits between macOS and your audio hardware. All system audio passes through the app, which plays it locally and makes it available as a recording source.

Music and players

Stream Spotify, Apple Music, VLC, or any macOS output audio into Gniark Live.

Per-app volume

Boost music, lower notifications or the browser without leaving the live.

Auto-pause music

Pauses Spotify or iTunes when another audio source starts (video, call, jingle).

Voice + system audio

Combine a USB mic and Background Music via an Aggregate Device to speak over the soundtrack.

Background Music or BlackHole?

Background MusicBlackHole
PriceFree, open sourceFree, open source
ApproachTakes system output, built-in monitoringVirtual driver, manual per-app routing
Per-app volumeYes (dedicated UI)No
Best forFull system audio, quick tweaks1 app → live, targeted setup
Need to route one app only?

To send only Spotify or GarageBand without capturing all of macOS, see the BlackHole or Loopback guide.

Prerequisites

  • macOS 10.15 Catalina or later (Intel or Apple Silicon)
  • Administrator rights to install the audio driver
  • Up-to-date Chrome, Firefox, or Safari for Gniark Live
  • Background Music must stay open during the live (it manages audio routing)

Install Background Music

  1. 1Download BackgroundMusic-0.4.3.pkg from GitHub Releases, or install via Homebrew: brew install --cask background-music.
  2. 2Run the .pkg file and follow the installer (admin password required).
  3. 3Open Applications → Background Music.app. On first launch, the app installs the driver and may restart the system audio service.
  4. 4Check Settings → Sound: Background Music appears as output (set as default on launch) and as input.

macOS permissions

  1. 1On first open, grant Microphone access to Background Music (required to expose the virtual device, not to spy on your mic).
  2. 2If you denied it: Settings → Privacy & Security → Microphone, enable Background Music.
  3. 3Restart Background Music.app and your browser before testing Gniark Live.
Device missing after install

Quit Background Music, run sudo killall coreaudiod in Terminal (the service restarts automatically), relaunch Background Music.app, and check Settings → Sound again.

Understand the audio flow

When Background Music is running, it becomes macOS default audio output. All application audio is sent there, played back on your headphones or speakers (pass-through), and copied to the Background Music input device that the browser sees as a microphone.

Flow: macOS apps → Background Music (output) → local monitoring + virtual input → Gniark Live.

Configure Background Music for a live show

Scenario A: stream system audio (music, jingle)

  1. 1Launch Background Music.app and keep it open.
  2. 2Play your music or jingle in any app (system output = Background Music automatically).
  3. 3In the Background Music menu bar icon, verify the source app volume is audible.
  4. 4In Gniark Live, select Background Music as the microphone (see next section).

Scenario B: adjust per-app volume

The Background Music UI lists active applications with a volume slider each. Lower unwanted apps (notifications, browser) and boost your music player before going live.

Auto-pause

Background Music can pause Spotify, iTunes, or VLC when another audio source starts. Handy between tracks, but test or disable this if you chain music and voice-over from multiple apps.

Scenario C: voice + system audio (Aggregate Device)

  1. 1Launch Background Music.app.
  2. 2Open Audio MIDI Setup (Applications → Utilities).
  3. 3Click +Create Aggregate Device.
  4. 4Check your physical microphone (USB, interface, built-in) and Background Music.
  5. 5Rename the device (e.g. Live Mix BGM).
  6. 6In Gniark Live, select this aggregate device as the microphone: voice and system audio are mixed together.
Monitoring

Background Music already plays audio on your real output: you hear what goes to the live without extra Audio MIDI Setup. Use headphones so the mic does not pick up speakers.

Select Background Music in Gniark Live

  1. 1Launch Background Music.app and verify a source is playing (quick test with a track).
  2. 2Open Gniark Live and start your stream.
  3. 3Allow microphone access, then choose Background Music (or your Aggregate Device).
  4. 4Validate with a test viewer or second browser before going public.
Do not quit the app

If you close Background Music.app, macOS restores the previous default output and the virtual device may disappear from the browser. Keep the app open for the entire live session.

Frequently asked questions

Is Background Music free?

Yes, open source under GPL-2.0. Free download on GitHub.

Why is microphone access requested?

macOS classifies the Background Music virtual device as an audio input. The app does not record your physical microphone.

Background Music or BlackHole?

Background Music for full system audio with per-app volume. BlackHole to route one specific app without changing system output.

Mix voice and music?

Create an Aggregate Device (mic + Background Music) in Audio MIDI Setup.

No sound in the live.

Verify Background Music.app is running, an app is producing sound, Gniark Live selected Background Music, and the source app volume is not zero in Background Music.

Apple Silicon compatible?

Yes, version 0.4.3 works on M1/M2/M3/M4 on recent macOS versions.

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