This is an easy-to-use, yet powerful audio file editor.
It works with a mixer built into a personal computer system, as well as external audio media.
It provides for the integration of effects: reversal, echo, phase vibrato (phaser), dynamic timbre change (wahwah).
In the editor, you can remove defects from the audio track: hiss, static noise, hum, and also adjust the pitch and tempo.
Works with formats: WAV, Ogg Vorbis, AIFF, AU, MP3, MPEG.

FluidSynth is a real-time software synthesizer based on the SoundFont 2 specifications and has become widely used. FluidSynth itself does not have a graphical user interface, but thanks to its powerful API, several applications use it and it has even found its way into embedded systems and some mobile applications.

Qsynth - GUI for FluidSynth.