How to set up beets on an existing library so that it doesn't change anything?

[halloleo]

I have played with beets a little bit an some smaller libraries and I like it. But I haven't used it with my main music library folder (which is served via Roon). I want to use beets to do some analysis on my music files like:

• Listing all genres I use in my music files

However at this stage I don't want beets to change or move any music file in my library folder. What's the best config set up for this?

Many thanks for any pointers!