FluidSynth is a console based real-time software synthesizer based on the SoundFont 2 specifications.
FluidSynth can read MIDI events from a MIDI input device and render them to an audio device using SoundFont instruments. SoundFont files are composed of digital audio “samples” and additional instrument parameters. These files can be created or downloaded off the Internet.
FluidSynth also has support for controlling effects in real time and can play MIDI files. Simply run fluidsynth with the SoundFont and the list of MIDI files to play.
A number of applications depend or use FluidSynth including Swami, QSynth, MusE, FluidGui, and The Miditzer. It has also been used in the MicrotonalISM project of the Network for Interdisciplinary Studies in Science, Technology, and Music.
The core synthesizer is written as a C library with a large application programming interface (API).
Key Features
- Render MIDI input or MIDI files to audio.
- SoundFont 2 support
- SoundFont 3 support (vorbis-compressed SF2)
- Microtonal support.
- Easy to integrate the synthesizer modules in various environments, as a plugin or as a dynamically loadable object.
- Realtime effect modulation using SoundFont 2.01 modulators.
- Built in command line shell.
- Playback of MIDI files.
- Shared library which can be used in other programs.
Website: www.fluidsynth.org
Support: Manual Page, Wiki, Mailing List (for developers), GitHub Code Repository
Developer: Tom Moebert and contributors
License: GNU Lesser General Public License 2.1+
FluidSynth doesn’t have a graphical user interface, For an attractive GUI interface for FluidSynth, check out Qsynth. Here’s an image of Qsynth in action.

FluidSynth is written in C. Learn C with our recommended free books and free tutorials.
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