Reverb

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🎵 Music Engine & Audio Pipeline ​

🏠 Documentation Hub > Features > Music Engine

Reverb's audio architecture is built on top of Moonlink.js, communicating with your audio server (NodeLink or Lavalink v4) over high-throughput WebSockets. It delivers sub-second track dispatching, real-time volume interpolation, dynamic audio filters, intelligent autoplay, and synchronized lyrics.

1. Supported Audio Sources ​

Reverb supports resolving audio tracks from:

  • YouTube Music (youtubemusic platform)
  • YouTube Standard (direct video, channel, or playlist URLs)
  • Spotify (Tracks, Playlists, Albums)
  • SoundCloud (soundcloud platform)
  • Apple Music
  • Deezer
  • Bandcamp
  • Twitch & Direct HTTP Audio Streams

Native Sources with NodeLink

When using NodeLink, all the sources above are natively supported out-of-the-box without requiring external Java plugins or maven downloads.

2. Advanced Audio Filters ​

Reverb provides direct hardware-accelerated DSP filters applied in real-time through the audio node:

CommandFilter AppliedEffect Description
r!bassboost [level]Equalizer (Low bands)Multiplies 20Hz - 125Hz gain up to +5dB for punchy low-end response.
r!nightcoreTimescale (speed: 1.2, pitch: 1.2)Accelerates track tempo and raises musical pitch.
r!vaporwaveTimescale (speed: 0.85, pitch: 0.8)Slows tempo and drops pitch for an atmospheric retro feel.
r!8dRotation (hertz: 0.2)Pans stereo audio smoothly between left and right ears.
r!tremoloTremolo (depth: 0.5, frequency: 2.0)Rapidly modulates volume for a fluttering sound.
r!vibratoVibrato (depth: 0.5, frequency: 2.0)Rapidly modulates pitch.
r!speed <value>Timescale (speed: value)Adjusts playback speed without modifying musical pitch.
r!pitch <value>Timescale (pitch: value)Transposes song key up or down.
r!clearfiltersResetClears all active DSP audio filters back to neutral.

3. Intelligent Autoplay ​

When enabled via r!autoplay or /autoplay, Reverb monitors queue depletion. When the last user-queued song finishes playing:

  1. Reverb queries for related recommendations based on the ID of the last played song.
  2. It deduplicates against previously played history in the session.
  3. It enqueues the top-ranked recommendation automatically, ensuring uninterrupted music playback 24/7.

4. Voice Channel Dynamic Status ​

When a track begins playing, Reverb updates the Discord voice channel status to display:

text
🎵 • <Song Title>

When playback stops or the player disconnects, Reverb cleans the voice status back to empty.

5. Synchronized Lyrics Integration ​

Reverb integrates LRCLIB (lrclib-api), an open, crowd-sourced synchronized lyrics database:

  • Executing r!lyrics or /lyrics queries LRCLIB for the current playing song.
  • If synced lyrics are found, Reverb renders formatted verses inside a clean, high-contrast message card.

6. Track Playback Lifecycle & Architecture ​

The following diagrams illustrate how Reverb resolves, schedules, and streams audio tracks through Moonlink.js and NodeLink:

Playback Decision Flow ​

Audio Dispatch Sequence ​

⏭️ Next Step ​

Read about Reverb's dedicated interactive music channel in Dedicated Song Requests Channel.