Adjusting the music volume also alters the sound volume, completely silencing the music output silences the sound output too. Both stable and unstable builds 2398 and 2399 (32/64 bit) are affected. I tried all possible music/sound path combinations (FMOD, SDL, OpenAL, DirectSound, Windows Multimedia), altering the volumes via menu slider and console commands, both from the launcher and the in-game start menu, relaunching Doomsday after changing the audio setup, all to no avail.
Also MIDI music output appears to be working only with the SDL_mixer, FMOD and Windows Multimedia only outputs some drum/percussion artefacts, but no actual music replay.
Running Windows 10 x64 Creators Edition here.