Unrealcpu wrote on 2020-11-05, 17:00:daemon tools available for pure dos?
If that was a solution, I would have mentioned it. While there is something called SHSUCDHD that can mount CD images in DOS, it cannot be used for CD audio.
It is programmatically very simple to play CD audio: a command is sent to the CD-ROM drive, which independently reads the data off the CD (note that nothing else can access the CD-ROM at the same time) and sends it directly to the mixer on the sound card. If the sound data is stored on a hard drive, then whatever other software is running has to be paused while the data is read – and then it has to be mixed with whatever other sound might be playing at the same time. This is not feasible in a single-tasking OS.
You could run DOSBox in pure DOS, but that kind of defeats the purpose of using "pure DOS". And there's ScummVM, but I'm not sure how that handles things.