How to use the command 'fluidsynth' (with examples)

FluidSynth is a command-line software synthesizer that allows users to turn MIDI files into audio. It synthesizes sound in real-time using SoundFont technology, which is a format that supports real samples of musical instruments. This capability makes FluidSynth an essential tool for musicians and composers who want to quickly generate sound from MIDI files. With its open-source nature, FluidSynth is versatile and widely used in different audio and music applications.

Use case: Play a MIDI file

Code:

fluidsynth --audio-driver=pipewire|pulseaudio path/to/soundfont.sf2 path/to/file.midi

Motivation:

Playing a MIDI file using FluidSynth can be immensely beneficial for a musician or composer who wants to hear their compositions directly from the MIDI without the need for additional equipment or software. It allows for immediate audio feedback and can help in critiquing and refining compositions. This command-line approach also facilitates integration into automated workflows, making it a handy utility in larger music production setups or scripts.

Explanation:

• fluidsynth: This is the main command that invokes the FluidSynth software. It prepares the system to take the subsequent arguments and synthesize MIDI into audio.

• --audio-driver=pipewire|pulseaudio: This option specifies the audio driver that FluidSynth should use to output sound. Choosing between pipewire or pulseaudio depends on your system configuration and the sound server you employ. PipeWire is a more modern solution that provides low-latency audio processing, while PulseAudio is a well-supported choice in many Linux distributions. This specification ensures that the sound generated from the MIDI file is audible through the system’s audio outputs.

• path/to/soundfont.sf2: The SoundFont file, represented here as path/to/soundfont.sf2, contains samples of the instruments that will be used for synthesis. This file is crucial because it defines how the MIDI notes are translated into sounds, offering the potential for a plethora of instrument voices and sound characteristics.

• path/to/file.midi: This argument represents the path to the MIDI file you wish to synthesize and play. MIDI files contain the sequence of notes and playback data, but not the actual sound. By interpreting this data using the SoundFont, FluidSynth produces a complete audio experience.

Example Output:

When executed, this command will output the audio represented by the MIDI file through the speakers. You’ll hear the synthesized sounds, orchestrated by the instrument samples defined in the SoundFont file. If all arguments are correct and appropriately directed, the fluid sound of instruments defined within the soundfont.sf2 linked with the sequence in file.midi will fill the room, allowing you to experience your MIDI composition as intended.

Conclusion:

FluidSynth serves as a robust tool for musicians and audio engineers looking to synthesize MIDI files into compelling audio. By leveraging the simplicity of a command-line interface and the rich sound capabilities offered by SoundFonts, FluidSynth empowers users with a streamlined, efficient process for rendering high-quality synthesized audio. Whether used for professional music production, educational purposes, or simply personal enjoyment, FluidSynth remains an invaluable asset in the digital musician’s toolkit.