A fully free and self-contained modular synthesizer based on the popular VCV Rack. Available in AudioUnit/CLAP/LV2/VST2/VST3 plugin formats and as a standalone app for FreeBSD, Linux, macOS, Windows and the Web.

A fully free and self-contained modular synthesizer based on the popular VCV Rack. Available in AudioUnit/CLAP/LV2/VST2/VST3 plugin formats and as a standalone app for FreeBSD, Linux, macOS, Windows and the Web.

Browser-based chiptune tracker for the demoscene. Compose XM/MOD/S3M/IT in the classic tracker style, on desktop and mobile, with live jams and a tiny intro replayer.

chiptrackr.com
github.com/wirehack7/webtracker
GameBoy online tracker ~ gb.chiptrackr.com
projectM is an awesome music visualizer. DISTRHO ProM makes it work as an audio plugin (CLAP, LV2, VST2 and VST3).

OnKey is a free, open-source singing trainer for the Mac. Play a song in Spotify, Apple Music, or YouTube in a browser, and sing along. The first time, you get the lyrics, and OnKey learns the singer’s melody when the song ends. After that, the notes scroll towards you, your pitch is drawn over them, and you get a score with a report on every line.
OnKey doesn’t provide, stream or download music. Your own music app plays it.
foo_audiomd5 is a foobar2000 component that calculates MD5 checksums of audio content using FFmpeg. It offers two modes:
Unlike format-specific integrity checks, foo_audiomd5 provides a common checksum field for use across supported audio formats. This makes it useful for cross-format audio comparison, library-wide deduplication and verification through foobar2000 queries or external tools. For FLAC files, it complements rather than replaces the format’s built-in integrity checks.
Open Preferences > Advanced > Tools > Audio MD5.
ffmpeg.exe. Recent versions accept either the containing directory or the full executable path.The results dialog supports sorting and context-menu actions. Version 0.7 also added scan-duration estimates.

Existing checksums: By default, the component skips tracks that already contain the configured checksum tag. To recalculate them, use the separate, hidden-by-default forced-rescan context-menu command. This is important when changing checksum modes.
Recalculating an existing library: If your library already contains compressed-audio checksums and you want to adopt PCM-based checksums, configure PCM mode and use the forced-rescan command. Otherwise, existing values may be left unchanged because the default scan skips tagged files.
Verifying results across formats: Select equivalent lossless files in different formats, calculate their PCM checksums and compare the resulting tag values. Matching values provide a convenient way to identify identical decoded audio.
Using decoder integrity verification: Version 0.7 added support for decoder integrity verifiers when calculating PCM checksums. Where supported, this lets the component use the decoder’s integrity-verification facilities as part of the process.
Large-library processing: The component supports multithreaded scanning. For very large collections, process manageable batches and review the results before continuing. Multiple foobar2000 instances are not necessary for normal operation.
Component: www.foobar2000.org/components/view/foo_audiomd5
Reference: en.wikipedia.org/wiki/MD5
AudioRouter is a visual audio router for Windows 11. Draw your audio on a canvas: plug a microphone into a noise gate, an EQ and a compressor, send the result to Discord, monitor it in your headphones and record it, all at once. Stream game audio from your gaming PC to your streaming PC over your home network. Every route is a picture you can read, and every setting is live.

Riff is an open-source, telemetry-free desktop music app and player for Windows, Linux, and macOS. It unifies playback across YouTube Music, YouTube, SoundCloud, and offline local media into a single high-performance interface without ads, subscriptions, or login constraints. Provides very fancy UI and layout.
Built with Electron, Vanilla JavaScript, and WebGL, Riff provides responsive UI interactions and hardware-accelerated audio visualization without runtime framework overhead. The project is distributed under the MIT license and enforces strict privacy: all configuration, cached streams, and playback history remain strictly on the local machine.
Features:
- High quality streaming with YouTube Music, YouTube, and SoundCloud without third-party advertisements or account requirements
- Offline lossless playback with full local library support for high resolution formats including FLAC, WAV, MP3, OGG, and M4A.
- Easy built-in audio editor, downloading with effects or trimming 10-band & 3-band equalizer, and real-time DSP effects (speed, pitch, reverb, distortion).
- 1-Click multi-platform playlist migration: Direct import and resolution of public playlists from Spotify, Apple Music, YouTube Music, and SoundCloud
- Material Design 3 UI: Dynamic color extraction from album artwork, deep UI theming, responsive layout presets, and an integrated CSS editor
- Hardware-Accelerated Visuals: Canvas and WebGL visualizers including real-time frequency analyzers, an interactive squiggly progress scrubber, and synchronized karaoke lyrics.
- Discord Rich Presence: Real-time playback status reporting track metadata, artist info, and elapsed time to Discord.
- Zero Telemetry: No tracking identifiers, analytics pings, or background data collection.
- Fullscreen mode with fancy lyrics animation.
- Albums – see all of your favorite artist albums.
- Customization – built in theme editor, configure everything, and a CSS editor, with animated backgrounds and interface opacity sliders.
- Plugins – built-in plugin feature where you can add a plugin to edit how Riff works with something or add a new function.
Extreme-fidelity synthesis of musical elements.
Music generates and manipulates sound in LPCM audio, sample by sample. It implements MASS (Music and Audio in Sample Sequences), a collection of psychophysical descriptions of musical elements expressed as equations and corresponding Python routines.
Music can synthesize musical notes, scales and chords, apply audio filters and effects, create spatial audio, and even sing lyrics to a melody. It is designed for precise sound synthesis, audio processing, and experiments with music and sound.
matrixmixer.lv2 is a matrix mixer π
It is available as a LV2 plugin and as a standalone JACK-application. The JACK application can run headless and be remote controlled via OSC.

NeoBleeper is the world’s first AI-enabled tune creation software using the system speaker (aka PC Speaker) on the motherboard, inspired by the Bleeper Music Maker software that Robbi-985 (aka SomethingUnreal) developed around late 2007-early 2008 but abandoned in 2011 due to the fact that beeps were directed to the default sound device instead of the system speaker on the motherboard in newer Windows versions. NeoBleeper provides a more stable music making experience by solving the problem of system beeps being directed to the default sound device instead of the system speaker on the motherboard in newer Windows versions by accessing the physical port of the system speaker.

Soundgrain is a graphical interface where users can draw and edit trajectories to control granular sound synthesis. Soundgrain is written with Python/WxPython and uses Pyo as its audio engine.

github.com/belangeo/soundgrain
linuxsynths.com/SoundgrainDemos/soundgrain
Servers, players, APIs and applications for building your own private music service
If you have a large music collection on your own hardware, there is a surprisingly mature open-source ecosystem for turning it into something that behaves a little like your own private Spotify. At the centre of that ecosystem is Subsonic and, increasingly, OpenSubsonic. The important thing about Subsonic is not a particular server or player. It is the fact that the server and the player do not have to come from the same project. Your music can live on one machine, be served by one application, and played through a completely different application on a phone, desktop, web browser or even foobar2000.
The architecture is simple:
YOUR MUSIC FILES β βΌ MUSIC SERVER β βΌSubsonic / OpenSubsonic β βββββΌβββββββββ βΌ βΌ βΌ Web Desktop Mobile
The server maintains the library and provides access to it. The Subsonic/OpenSubsonic API provides the common language. Clients use that API to browse, search, stream and control the collection. OpenSubsonic is an open, collaboratively maintained API built on the original Subsonic API, while maintaining backward compatibility with the existing protocol. That makes it possible to mix and match applications in order to suit everyone’s requirements.
The server is the part that knows where your music is and what makes it available. Several open-source servers participate in the Subsonic/OpenSubsonic ecosystem.
Navidrome is probably the most visible modern example. It is a lightweight, self-hosted music server with its own web interface, transcoding, multi-library support and a large ecosystem of compatible applications. It is GPLv3 software. Navidrome currently supports Subsonic API 1.16.1 with some differences and is continually adding OpenSubsonic extensions. Its important characteristic is that Navidrome is not dependent on its own player. You can use its web interface, or choose from a large collection of third-party clients.
gonic is another lightweight Subsonic/OpenSubsonic server, written in Go. It is particularly interesting if you want a relatively small server rather than a large media-management application.
Airsonic-Advanced continues the Airsonic branch of the Subsonic family. It is useful for people who want to remain closer to the traditional Subsonic/Airsonic lineage while still having a maintained open-source implementation.
Ampache takes a different approach. Ampache is a broader web-based media server rather than simply a lightweight Subsonic server, but it can act as a Subsonic/OpenSubsonic server for compatible clients. Its current documentation shows OpenSubsonic becoming the default implementation, with the traditional Subsonic API retained for compatibility.
Subsonic’s original API has become a de facto standard for self-hosted music applications. OpenSubsonic is the community effort to continue developing that API. The goal is not to throw away Subsonic and start again. Instead, OpenSubsonic extends it while maintaining compatibility. The API covers much more than simply “play this file.”
It includes:
It also distinguishes between browsing a collection through its metadata and browsing its underlying file structure. That distinction is particularly important for a serious music library. The API is becoming more capable as OpenSubsonic extensions are added, and servers can advertise which extensions they support.
This is where the ecosystem becomes interesting. A server does not dictate the application you use to listen to your music. Navidrome’s current application catalogue lists dozens of clients for Android, iOS, Windows, Linux, macOS, web and other platforms.
Among the open-source projects are applications such as:
The OpenSubsonic project itself maintains lists of participating servers and clients.
There are also proprietary clients, which is an important part of the ecosystem. Subsonic compatibility does not mean that every application is open source. The protocol is the common layer.
For audio-file.org readers, there is another particularly interesting option:
foobar2000 can now act as an OpenSubsonic client.
The foo_opensubsonic component connects foobar2000 to OpenSubsonic-compatible servers such as Navidrome. It can:
It can even expose streamed tracks through subsonic:// paths. The current component supports foobar2000 v2 on Windows, including Windows ARM. That creates an interesting combination:
Music files β βΌ Navidrome β βΌOpenSubsonic β ββββββββββββΊ Mobile player β ββββββββββββΊ Web player β ββββββββββββΊ foobar2000
In other words, your server becomes a music-library backend, while foobar2000 remains one of your preferred music environments.
Subsonic/OpenSubsonic does not have to be the final destination. Music Assistant can use OpenSubsonic-compatible servers as music sources. This creates another layer:
βββ foobar2000
β
Music Server βββ OpenSubsonic βββ mobile
β
βββ Music Assistant
The result is closer to a complete home music system than simply a remote music player.
The important thing is the separation of roles.
| Application | Role |
|---|---|
| Navidrome | Music server + web player |
| gonic | Lightweight music server |
| Airsonic-Advanced | Subsonic-family music server |
| Ampache | Full media server + Subsonic/OpenSubsonic server |
| Feishin | Desktop/web client |
| Supersonic | Desktop client |
| Tempus | Android client |
| Airdrome | Web/PWA client |
| foo_opensubsonic | foobar2000 client |
| Music Assistant | Music-system integration layer |
This means you can build several different systems from the same collection.
Music files βNavidrome βNavidrome Web UI
Music files βNavidrome βOpenSubsonic βAndroid / iOS client
Music files βNavidrome βOpenSubsonic βfoo_opensubsonic βfoobar2000
Music files βNavidrome βOpenSubsonic βMusic Assistant βmultiple players / rooms / clients
There isn’t one universal answer because the components solve different problems.
foo_opensubsonic is the obvious bridge.The important point is that these choices are not mutually exclusive.
The really interesting part of the Subsonic ecosystem isn’t streaming. It is separation. Your music collection doesn’t have to be tied to one application.
YOUR MUSIC
β
ββββββΌβββββ
β SERVER β
ββββββ¬βββββ
β
OpenSubsonic
β
ββββββββββββΌβββββββββββ
βΌ βΌ βΌ
foobar mobile web
β
βΌ
your preferred
music environment
The server can change.
The player can change.
The phone can change.
The user interface can change.
The underlying music collection remains yours.
And because the API includes metadata, playlists, ratings, playback information and other library operations, it provides considerably more than a simple mechanism for delivering audio files.
OpenSubsonic is still developing.
That is particularly significant because newer extensions are beginning to move beyond the original “music streaming server” model. For example, current implementations are adding standardized mechanisms for playback reporting, lyrics, transcoding and other capabilities. There is even work appearing around sonic similarity.
Ampache’s current OpenSubsonic implementation documents a sonicSimilarity extension that can expose audio-analysis-based similar tracks when an appropriate analysis system is installed. That points toward something much more interesting than simply putting your music on a web server. It points toward a common interface between:
music collection β metadata β analysis β recommendation β player
And that is where this ecosystem becomes particularly interesting for anyone trying to build a genuinely intelligent music library.
Subsonic/OpenSubsonic is best thought of as an interoperability layer for personal music systems. You don’t have to choose one monolithic application. You can choose a server for your collection, an API for interoperability, and the players you actually like. For someone building a serious personal music library, that separation is a feature, not a complication.