While its not abnormal for the complete sound track to be missing, I feel as if I should mention it. The same is true for Divinity: Original Sin, though in that case the missing tracks can be found (even if in a lesser form) from other games in the series. That is not the case here. Not all in-game music is included in the sound track, in fact most of the better tracks are absent.

That's a pity. Do you know which songs in particular are missing? I just unpacked the FLAC version and there are 17 of them.

The soundtrack is basically most of the overland music arranged into "suites" according to the region where they play. So I think most of the fight music, boss music, dungeon music, as well as the expansion music is not in the soundtrack.

The good news is you can easily extract the full soundtrack yourself. If you go to <installation folder>/pak and look for the zip files called "musichq.zip" you can extract the songs on .ogg format. This worked in the disc version at least.

This is only true, when the flac is based on the uncompressed original recordings and not (like in most cases) on an already lossy remix. In the last case using flac is complete nonsense, even if you plan to convert it later...

Well sorry you're disappointed by that option, since I don't think you're going to get anything better. I enjoy the extracted soundtrack a lot myself. The information's there for posterity I guess.

The OST is indeed incomplete, but not in the sense the OP is talking about.

The OST provided by GOG is based on the official soundtrack CD, which was available via the Collector's Edition of Sacred 2. However, that CD had 18 tracks, whereas the OST available from GOG only has 17. The last track, Big Machine, is missing.

I've already informed support about this. So the last track will hopefully be added soon.