I just got The Angel of Darkness running, what a trip down memory lane.
While mechanically not the strongest in the series, it's incredibly ambitious and has one of the most unique atmospheres.
To top this, it has, to me one of the best soundtracks in the series.

In 2019 a kickstarter was launched to remake the OST with modern equipment. I thought it failed; but apparently it didn't!
I'm probably late to the party, but had to share it for those who missed it too.

So, Peter Connelly has re-recorded some of the OST's for The Last Revelation, Chronicles and Angel of Darknesswith an orchestra (recorded at the Air Lyndhurst Studios, London) , as well as remastered the originals.

The remade album, Dark Angel Symphony, is streamable for free.
https://orcd.co/brr001
The download and buy options are dead links, but can be found through a quick search.(not sharing the link in case those are less than legal).

Here's a nice article about how the project came into being. A very relatable story of how those games helped me too through some very rough times.
Enjoy!