Trying to call functions from other classes

I'm trying to get FMOD working but I just can't get the main() to call it

int main()
{
  cout << "Us开发者_运维技巧ing FMOD \n";
  cout << "Select a Track: 1-5 Horror \n";
  cin >> HorrorTrack;

  AudioProject *pAudioProject = new AudioProject;
  pAudioProject->initAudio();
  //AudioProject::initAudio();
  MainPage(); // Main Page Function
  
  if (pAudioProject)
  {
      delete pAudioProject;
      pAudioProject=NULL;
  }
  
  char f;
  cin>>f; 
  return 0;
}

The errors I'm getting are:

unresolved external symbol "public: __thiscall AudioProject::AudioProject(void)" (??0AudioProject@@QAE@XZ) referenced in function _main

1>C:\Users\CodeMonkey\Desktop\AudioProject\Debug\AudioProject.exe : fatal error LNK1120: 1 unresolved externals.

Which is from the .h file variables which are declared public. However, if I make the initAudio anything but public I wont be able to access it in my main() function. Any ideas?

---

You haven't linked the library, so the definitions of symbols that it exports cannot be found.

Read this "FMOD"'s instructions.