Install fluid-soundfont-gm by entering the following commands in the terminal:
sudo apt update sudo apt install fluid-soundfont-gm
Description:
Fluid (R3) General MIDI SoundFont (GM)
This is a GM SoundFont, for use with any modern MIDI synthesiser: hardware (like the emu10k1 sound card), or software (like FluidSynth). . This package provides the larger GM sound set, without the Roland Sound Canvas extensions.
Version: 3.1-5.1
Section: universe/sound