Now I got to messing around with the HoMM1 music too, and here's an interesting discovery: the 16-bit audio tracks for DOS and the Windows CD audio are not of the same quality! The CD audio version is actually quite a bit better, but it's more meant for listening and not playing in the game itself.
To test this, what I did is I opened the 16-bit audio files (.62s) from the DOS CD in Audacity (they're raw PCM, 16-bit, 22050Hz, little endian), saved it in FLAC format, then ripped the same audio files from the Windows CD directly into FLAC and opened both in Audacity.
This is how they look side by size, zoomed out:
Top is Windows CD audio, bottom is 16-bit DOS audio. What's very obvious is that the DOS audio is much louder and seems to be made specifically for looping, as it doesn't fade in and out. Here's an extreme zoom in:
Here the difference is obvious too. The DOS version looks jagged, whereas the CD audio version is smooth. This is thanks to the fact that the CD audio is 44100Hz, while the DOS audio is 22050. Also, if you look closely, you'll see that the audio channels don't actually match perfectly! It's even more obvious when you look at the spectrogram:
Notice how even the positioning of the instruments relative to one another doesn't actually match between the versions! Also, if you zoom out all the way in Audacity:
...the DOS audio doesn't actually zoom out, while the CD audio does. Let's also look at the range maps. The DOS audio:
The CD audio:
Meaning that the DOS audio's range is cut off at 11 KHz, while the CD audio has a full range.
So, in conclusion, CD audio is of much better quality than DOS audio, except when it comes to loopability, as the CD audio has added fade out.
Unfortunately for me, Wine doesn't actually run the Windows version correctly.
...wait a minute, since the DOS files are raw PCM, I wonder if it's possible to reverse the process and make high quality .62s files. Hmmmmm... But would DOS play back 44.1k correctly, or slowed down, I wonder.
Oh, and the question about how to make the tracks in the DOS version continue playing from the middle rather than restart is something I'd like to know the answer to too.