The game: "Animal Math" by Donald Pavia (1986, open source Pascal)
http://www.abandonia.com/en/games/25142/Animal+Math.html
The problem: PC Speaker song plays at about 10x normal speed with Dynamic Core.
Auto Core sporadically has the same problem.
The song is supposed to take about 20 seconds to play, but it can be over in
as few as 2 seconds in DOSBox. The song plays at normal speed in real DOS
on my Core2Duo laptop.
I can only reproduce the problem with cycles set to a high fixed value or max. Both are generally a bad idea with a game from 1986.
Correct about the high fixed value and the max settings.
The note about 1986 games needed to be slowed down is generally true, but in real DOS at 1.4GHz (much faster than DOSBox can emulate) the song plays at normal speed, which means that this isn't just a problem with an old DOS game that lacks a proper timer. There seems to be something specific with DOSBox "Dynamic Core" that makes it treat the song as a special case.