I had a HD crash, so I reinstalled SFC1. It worked fine. Then I reinstalled also the Chris Jones/Lansing/etc. old AGT system to switch mods/eras.
Now the background music does not play, though the special effects sounds (phasers, explosions, beeps) do come on when they're supposed to.
I do recall I had this problem a long time ago when I first fiddled with AGT, but I forgot what I did.
I would appreciate anyone who can help.