The IDirectMusicPerformance::GetGlobalParam method retrieves global values from the performance.
HRESULT GetGlobalParam(
  REFGUID rguidType, 
  void* pParam,
  DWORD dwSize
);
 If the method succeeds, the return value is S_OK.
If it fails, the method may return one of the following error values:
| E_INVALIDARG | 
| E_POINTER | 
If rguidType isn't in the list of global data being handled by this performance, the method returns E_INVALIDARG. Make sure to call SetGlobalParam first.
  Windows NT/2000: Requires Windows 2000.
  Windows 95/98: Requires Windows 95 or later. Available as a redistributable for Windows 95.
  Header: Declared in dmusici.h.
IDirectMusicPerformance::SetGlobalParam, IDirectMusicPerformance::GetParam, Music Parameters