I did not have these problems when I originally purchased the game a few years ago. As of now, the game is using some horrible versions of the town themes (the ones without the opera). I think these are the expansion tracks that are replacing the originals. Or is it the other way around? Either way, I want my original tracks back.

I've tried downloading the soundtrack provided by GOG, however, it's in MP3 format, and the game won't run if I simply replace the MP3s with the .ogg files. I tried using winLAME to convert the .MP3s to .oggs, but when I did that, the sound quality was murdered terribly, even when I made sure to use a bitrate of 320 (the same as the original MP3s).

So all I've managed to do thus far is replace the current .oggs with bad quality versions of the originals. I have not been able to find any downloads of the soundtrack in .ogg format. I don't know why GOG broke things with this update, because I don't really want to play HoMM2 without the proper town music.

Here. You need to ask CRW about the files, though.

I think there are 2 versions of Heroes 2: The DOS version and the Windows version - available as a bonus content. Both version have the same music quality?

When you say the game is using some horrible version of the town themes, how do you mean? As far as I know, there are only two versions for the ingame music, CD audio and MIDI. The game isn't playing the MIDI version by any chance is it?

At first, I was unsure about getting HOMM2 from GoG as I was afraid the DOS version wouldn't have the CD audio like the CD version I bought many moons ago. I was glad to see that the game themes are exactly how I remember them so I'm kinda wondering what this horrible version is assuming what you're listening to isn't the MIDI.

By horrible music he means PoL town themes. Some ppl do not like it.

I'm talking about whatever soundtrack they replaced the sweet opera themes with. For example, this awesome theme: https://www.youtube.com/watch?v=7qfkpokX9EY (one of the best reasons to play Necromancer) was replaced with: https://www.youtube.com/watch?v=dZW1UyvN5LI

Yuck. That solution worked perfectly! Once I got Foobar to cooperate, the conversion and file replacements went off without a hitch. Thanks!