I would expect SetMusicMasterVolume (0) to reduce the volume to zero, thus making the music inaudible; this doesn't actually happen. On my system, setting it to 0 is about half as loud as setting it to its maximum of 100.
Spoiler
Err.... wtf?
void SetMusicMasterVolume(int newvol) {
if ((newvol<0) | (newvol>100))
quit("!SetMusicMasterVolume: invalid volume - must be from 0-100");
==> play.music_master_volume=newvol+60; <==============================
update_music_volume();
}
EDIT:
The 3.2 manual suggests that SetMusicMasterVolume() function is deprecated.
Try using System.Volume or Game.SetAudioTypeVolume().
Right. Thank you :)