Emblem Round — catalogue of the system
Plate 00 · GPL-3.0
MZ.000
Accession
Free forever · open source · no account
A free, open source music player for the music on your own Plex, Jellyfin or Subsonic/OpenSubsonic server. On iPhone, iPad, Android, Mac, Windows and Linux. Your library, listening history and taste sync between them on their own, so playback carries on wherever you pick it up.
Runs on6 platforms, one library
The stamp used on every plate below
MZ.001
Sources
A Plex, Jellyfin, or Subsonic/OpenSubsonic server with your music on it. Navidrome is the tested OpenSubsonic target; other compatible servers are best-effort.
Sign in with your Plex account and pick a library.
Quick Connect or a plain username and password.
The tested OpenSubsonic server; other compatible servers are best-effort.
Your serverPlex · Jellyfin · Subsonic
iPhone
iPad
Downloaded
MZ.002
Holdings
Connect Plex, Jellyfin, or a Subsonic/OpenSubsonic server such as Navidrome. Mozz syncs its catalog into a local database, so browsing and search stay fast when the server is unreachable.
Sleeves and titles shown are drawn placeholders. Your catalogue is whatever is already on your server.
MZ.003
Editions
The desktop app on Windows, macOS and Linux shares the same library, listening history and taste as the phone in your pocket, and keeps itself in step without being asked. Leave off on one device and Mozz can offer to pick playback up on another.
A — One library on every machine
Sign in on a second device and the same library, the same listening history and the same taste are already there. Nothing has to be exported, matched up or carried across by hand — and there is still no Mozz account in the middle of it.
B — Carry on where you stopped
Leave off on the desktop and the phone can offer to pick the same track up from the same second. It is opt-in, and it is an offer: playback is never yanked away from the device you are actually listening on.
Albums
6 results · searched on device
Filed Under Home
Clerk of Waves
downloaded · plays with no signal
MZ.310A little extra on Apple hardware: Between your Apple devices, iCloud Keychain carries the server sign-in across, and Handoff passes the album, artist or playlist you are looking at straight to the one in your hand.
MZ.004
Discovery
Three things, in one line. The catalogue is read, the audio is analysed, and both weekly playlists are selected out of that — on your device, from music you already own.
A
B
C
Your libraryalready on your server
Sonic analysistempo · energy · texture
The weekMozz Weekly · Discover Weekly
Mozz listens to the audio itself and describes each track by how it sounds — tempo, energy, brightness, texture, key. That fingerprint is what lets the app tell two albums apart when the genre tag says they are the same thing.
A fresh set every week, drawn from the music you play most and the music that sits next to it. It is put together on your device and stays available offline, so the week does not stop working when the server does.
The other half of the week: the parts of your own catalogue you have not reached for lately, chosen because they sound like what you have been playing. Albums you already own, surfaced again — nobody paid for the placement.
MZ.005
Two modes
Streamingfrom the server you run
Offlinefrom the device in your hand
One library
A — Streaming
Play straight off the machine in the other room, over your own network. The interface does not change between server families, because the app is reading your catalogue rather than someone else's.
B — Built to work offline
Downloads are part of the design, not an afterthought bolted on later. Take an album on the subway and it behaves exactly like it does at home.
No signal
Still playing
Downloads
Download anything and it plays offline. The catalog is stored on the device, so browsing and searching work with the server unreachable.
MZ.006
The register
The whole catalogue lives in an on-device database rather than behind a request to the server, so the list narrows while you are still typing — and it keeps narrowing with the server switched off.
12 shown
g
7 shown
gl
4 shown
gla
2 shown
glass
1 shown
MZ.007
Capabilities
Everything it does, entered one plate at a time. All of it is in the free app, because there is no other kind.
Connect Plex, Jellyfin, or a Subsonic/OpenSubsonic server such as Navidrome. Mozz syncs its catalog into a local database, so browsing and search stay fast when the server is unreachable.
CATDownloads are part of the design, not an afterthought bolted on later. Take an album on the subway and it behaves exactly like it does at home.
OFFThe whole catalogue lives in an on-device database rather than behind a request to the server, so the list narrows while you are still typing — and it keeps narrowing with the server switched off.
FTSAn album that was mixed to run together still runs together: no silence inserted between tracks, and no crossfade you did not ask for.
CUEMusicBrainz and ListenBrainz can sharpen radio, mixes, and shuffle when enrichment is enabled. Turn it off and local genre-based recommendations still work.
RADMozz Weekly and Discover Weekly are both built from music already in your library. They are assembled on your device and stay available offline, so discovery never depends on a subscription service.
WKYA proper equalizer, plus playback that respects the file you actually own instead of quietly re-encoding it.
EQSiri plays a song, album, artist, playlist, genre, liked songs or a mix straight from your own library — including from a HomePod, which has no apps of its own and hands the request to your iPhone to play and AirPlay back.
ASKNo gap
Track 01
Track 02
Low
High
10 bands
HomePodno apps of its own
Asked out loud
iPhoneresolves it, then plays it
Your libraryalready on the device
AirPlayed back
Radio
MusicBrainz and ListenBrainz can sharpen radio, mixes, and shuffle when enrichment is enabled. Turn it off and local genre-based recommendations still work.
Voice
Siri plays a song, album, artist, playlist, genre, liked songs or a mix straight from your own library — including from a HomePod, which has no apps of its own and hands the request to your iPhone to play and AirPlay back.
MZ.008
Conditions
There isn't one. It is your library, on your hardware, and the app has no claim on it.
There is no Mozz account and no Mozz server. Sign in only to the media server you already run.
No analytics, telemetry, or ad networks. Optional lyrics and recommendation enrichment contact only the named open services when enabled.
Free forever, and open source under GPL-3.0. Every feature is in the free app, because there is no other kind.
Your files stay yours, on hardware you control. Walk away whenever you like and the music is still there.
MZ.009
Queries
MZ.010
Closing
Your files, on hardware you control, played by an app with no reason to know anything about you.