Check the playing status of the music stream.
Defined in <SDL_mixer.h>
int Mix_PlayingMusic(void);
(int) Returns non-zero if music is playing, zero otherwise.
If music is currently playing, this function returns 1. Otherwise it returns 0.
Paused music is treated as playing, even though it is not currently making forward progress in mixing.
This function is available since SDL_mixer 2.0.0.