I don't think those speakers are capable of voice. They can handle a few different beep tones and that's about it. The song was not like listening to Spotify, it was played using beep tones.
I had an Athlon motherboard with voice POST messages… one night I woke up to it saying “your CPU has a problem!” over and over and was freaked out until I was completely awake and figure out what was wrong.
It wasn’t high quality coming through the piezo speaker, but it was good enough.
I definitely remember short 2 or 3 second clips of relatively high quality music being played through our family's IBM XT's motherboard speaker at one point using a demo we got from a BBS or the Public Domain Software site in the mid-80s. It wasn't easy but some madman made a proof-of-concept that did it and it was incredible at the time.
You could just about play speech using one bit output using pulse-width-modulation. But it was almost unrecognizable. And would take a lot of memory for the time.
It was usual to have different numbers of beeps for POST errors.
But this was an age when a PC would say "Keyboard error. Press any key to continue", so things were not thought out that well.
If your keyboard was actually working, you pressed a key. If it was not working, you went to get new keyboard. What is "not thought through" about that?
Tip: be passive aggressive and sarcastic when helping them. It both teaches them the solution in a memorable way, makes them not want to get help from you again, AND makes them think twice before doing so.