In Goldwave, this is stupidly easy. They even have about 10 presets for this. I looked at the presets and made my own.
Pick a threshold minimum and maximum and it reduces the volume of those portions across the whole track or within a selected area, like a few seconds down to the minimum. It does not touch the volumes below of the spread you've selected. You can raise or lower that spread of db to suit your taste.
Goldwave also has the reverse, which takes lower db sections, again within a range and boosts that spread within a track or a selection within that spread only, so quiet piano parts are boosted but loud cymbal crashes are not.
What I do is a batch file processing, compressing the volume at a very high db level, so it is not very noticeable at all, then the reverse ever so slightly, then compress again etc. With Goldwave, I can take a whole 2 hour show and program the batch commands, multiple light compression, boosting, compression boosting etc, and it processes the file overnight and even saves it. So in the morning, I'm ready to look at it one last time for tweaks and file splitting.