SDL_mixer / Mix_VolumeMusic

I’m using the SDL_mixer and want to change the Music-Volume on wav-Files,
but the changes with Mix_VolumeMusic don’t take place
So i read about a patch for this problem, which was posted by
King of the Bongo on gmane.comp.lib.sdl
Is there any official patch or do i have to use this solution to solve
this problem ?
Maybe i’m wrong and this is no bug in the sdl_mixer
if so, it would be nice, if anybody could show me how to use
Mix_VolumeMusic correctly

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