For recording level music of for example Heretic, Hexen, ... (or any FPS) DRO has the advantage over WAV because DRO only captures the OPL commands, so it will only capture the level music.
If you record to WAV you record everything including the sound of the enemies, ...
So an easy way to record level music (if you want it to be WAV format):
- record using DRO
- export the DRO to WAV by using for example https://audacious-media-player.org/
(use the filewriter to export to WAV)
Recording it directly to WAV in dosbox would be much more difficult. You have to disable the sounds in the game (if even possible) of the enemies, ...
MS-DOS music addict - DOSBox/AdPlug enthusiast