Sorry to be pedantic, but what is 'the General Midi 1 soundfont'?

Usually, a 'soundfont' is a file of digital data (like .wav or mp4 data) to be used to create the sound of instruments. There is certainly not ONE of such a file, I'm sure there are a number, of varying size and quality, some free, some costing money. I use one called 'Timbres of Heaven' and it's quite good. I've heard some pretty poor ones as well.

There are certainly files providing sounds for GM instruments (i.e. GM1, or just GM). There are other files with extended facilities, but maybe not as far as full GM2, as GM2 is a LOT bigger than GM

The list of instruments for GM is pretty standard, so you can find 'the list'. I have seen lists for GM2, but these tend to vary (somewhat) between manufacturers so I'm not certain that GM2 is as 'standard' as is GM (1). Standard enough for most purposes, I guess. But not 100%??

Coming back to 'soundfont' files, if there are any complete enough to be worthy of the name, they may not be 'standard' enough to count??

Geoff

General midi 1: https://www.midi.org/specifications-old/item/gm-level-1-sound-set

Hi,
I thought I might be able to help clear this up... General Midi System Level 1 and General Midi System Level 2 do not define specific sounds, It defines a set of shared features that can be used to describe a sound as well as standard patch's or program numbers for where that sound should go.
From the GM1 Spec document
[code type=markup]
General MIDI Sound Generator Requirements
Synthesis/Playback Technology (Sound Source Type):
• Up to the manufacturer.
Number of Voices:
• A minimum of:
1) 24 fully dynamically allocated voices available simultaneously for both melodic and
percussive sounds; or:
2) 16 dynamically allocated voices for melody plus 8 for percussion.
MIDI Channels Supported:
• All 16 MIDI channels.
• Each channel can play a variable number of voices (polyphony).
• Each channel can play a different instrument (timbre).
• Key-based Percussion is always on channel 10.
Instruments:
• A minimum of 128 presets for Instruments (MIDI program numbers), conforming to
the "GM Sound Set" (see Table 2)
• A minimum of 47 preset percussion sounds conforming to the "GM Percussion Map"
(see Table 3)"
[/code]

So basically you must include 128 sounds that conform to the GM Sound Set. but these sounds can be generated in any number of ways. Windows 10 by default comes with a GM1/2 and Roland GS Sound Set Synth which (supposedly) uses wave table synthesis. Microsoft Documentation

--TLDR--
Probably the best example i can give is WAY back in high school i got the PC/Windows version of Final Fantasy 7. (i promise this will make sense). FF7 made use of SystemMidi (or Playstation MIDI if on console) for background music. On the PC though i had routed the actual midi from my sound-card to a Yamaha GM Synth . Both the System Midi and The Yamaha were "General Midi" compliant... but the Yamaha sounded a thousand times better because it used a Sampled synthases rather than whatever the Sound blaster 16 used.