OpenAL alSourcePlay() in a detached thread

I am trying to play music using C++11 threads. After initializing OpenAL, I have the following code within my Music::Play() method:

alSourcePlay(source);

ALint source_state;
alGetSourcei(source, AL_SOURCE_STATE, &source_state);

while (source_state == AL_PLAYING) {
  alGetSourcei(source, AL_SOURCE_STATE, &source_state);
  alGetSourcef(source, AL_SEC_OFFSET, &song_time);
}

Since this while loop is blocking, I have to run it in a separate thread from my main program logic. I tried adding the following to main():

Music music;
std::thread tmusic(&Music::Play, &music);

...and it all worked fine. I then decided to move this functionality to a method in my main program class:

Program::PlayMusic() {
  Music music;
  std::thread tmusic(&Music::Play, &music);
}

I figured that this was not working because the thread object was immediately going out of scope after Program::PlayMusic() ended, and the thread was destroyed. I tried detaching the thread from the thread object using tmusic.detach(), and that seemed to work okay, but the music only plays some of the time. It seems to be related to the size of the track. My original song was a ~350MB WAV file that I was loading using:

buffer = alutCreateBufferFromFile("music.wav");

trimming the file down to ~4MB seems to help, but still it only plays some of the time. Any help would be greatly appreciated!