Kira,
Depends on the Operating System you use how you get sound output.
Windows -- requires some software like Virtual Midi Synth (
https://coolsoft.altervista.org/en/virtualmidisynth) which you install and run (it will show up in the Windows Task bar). When you start Frescobaldi, in its Midi settings you can select the process ID value for VirtualMidiSynth. You will need a soundfont for any of this to work. The VirtualMidiSynth download page has a list of free soundfonts (
FluidR3_GM is a very good GeneralMidi sound font).
Linux -- a bit more complicated. It's easiest with 2 bits of software, fluidsynth and QSynth. QSynth requires fluidsynth, so you must have both. QSynth makes configuring fluidsynth easy (which is why most people use it). Make sure that QSynth is configured for the correct output device (ALSA most likely, and almost surely NOT jackd [which requires another whole set of software]) and soundfont (like VirtualMidiSynth above - you can still use VMS website to get a sound font -- but I think if you can install QSynth/fluidsynth you Linux distribution package manager probably also has a soundfont you can install). QSynth's settings allow you to specify the "name" of the fluidsynth process, which you can then "see" and select in Frescobaldi's settings. Run QSynth *before* Frescobaldi to get fluidsynth going, then in Frescobaldi configure it to use QSynth. QSythn has its own volume for fluidsynth output independent of you computer's volume so make sure it's actually loud enough to hear (you'll see it on the QSynth application UI on the left).
MacOS -- LONG ago I used to use Homebrew on a MacOS laptop to install and use QSynth/fluidsynth, so I know at one point that was possible. Perhaps it still is, but I cannot say for certain. Other users on this email list may have more recent experience with MacOS.
Regards,
Guy S
--
“Happiness is the meaning and the purpose of life, the whole aim and end of human existence.”
― Aristotle