Playing mid without sound~~~

My code is as follows:
FMOD::System *system;
system->init(64, FMOD_INIT_NORMAL, nullptr);
FMOD::Sound * sound = fsystem->createSound(“xxx.mid”, FMOD_DEFAULT, 0, &sound);
FMOD::Channel *channel = 0;
fsystem->playSound(sound, 0, false, &channel);

Why is there no sound?
But playing MP3 is normal.

All the FMOD functions return FMOD_RESULT, check all of these to see if something is going wrong.

Thank you for settling it.

Require support for gm.dls file