Step 6: Shutting Down DirectMusic

Before exiting, the program must unload the instruments, release all the objects that have been created, and dereference COM (remember, every call to CoInitialize must have a matching call to CoUninitialize).

The following function performs the necessary cleanup:

HRESULT FreeDirectMusic()
{
    // If there is any music playing, stop it. This is 
    // not really necessary, because the music will stop when
    // the instruments are unloaded or the performance is
    // closed down.
    g_pPerf->Stop( NULL, NULL, 0, 0 );
 
    // Unload instruments – this will cause silence.
    // CloseDown unloads all instruments, so this call is also not 
    // strictly necessary.
    g_pMIDISeg->SetParam(GUID_Unload, -1, 0, 0, (void*)g_pPerf);
 
    // Release the segment.
    g_pMIDISeg->Release();
 
    // CloseDown and Release the performance object.
    g_pPerf->CloseDown();
    g_pPerf->Release();
 
    // Release the loader object.
    g_pLoader->Release();
 
    // Release COM.
    CoUninitialize();
 
    return S_OK;
}