HRESULT STDMETHODCALLTYPE ProgramChangeTool::ProcessPMsg( IDirectMusicPerformance* pPerf, DMUS_PMSG* pDMUS_PMSG )
{
	if (pDMUS_PMSG->dwType == DMUS_PMSGT_PATCH)
	{
		
		if(( NULL == pDMUS_PMSG->pGraph ) || FAILED(pDMUS_PMSG->pGraph->StampPMsg(pDMUS_PMSG)))
		{
			return DMUS_S_FREE;
		}
                        DMUS_PATCH_PMSG* pMsgNote = (DMUS_PATCH_PMSG*) pDMUS_PMSG;
			pMsgNote->byInstrument = 0x1D; //overdriven guitar 
				
		pPerf->SendPMsg((DMUS_PMSG*)pMsgNote);
	}

	return S_OK;
}

HRESULT STDMETHODCALLTYPE ProgramChangeTool::Flush( IDirectMusicPerformance* pPerf, DMUS_PMSG* pDMUS_PMSG, REFERENCE_TIME rt )
{
	
	return S_OK;
}

ProgramChangeTool::ProgramChangeTool()
{
	
	m_cRef = 1;
	m_boolToolOn= false;

}

ProgramChangeTool::~ProgramChangeTool()
{
	

}

STDMETHODIMP ProgramChangeTool::QueryInterface(const IID &iid, void **ppv)
{
    if (iid == IID_IUnknown || iid == IID_IDirectMusicTool)
    {
        *ppv = static_cast<IDirectMusicTool*>(this);
    } 
    else
    {
        *ppv = NULL;
        return E_NOINTERFACE;
    }
    
    reinterpret_cast<IUnknown*>(this)->AddRef();
    return S_OK;
}

STDMETHODIMP_(ULONG) ProgramChangeTool::AddRef()
{
    return InterlockedIncrement(&m_cRef);
}

STDMETHODIMP_(ULONG) ProgramChangeTool::Release()
{
    if( 0 == InterlockedDecrement(&m_cRef) )
    {
        delete this;
        return 0;
    }

    return m_cRef;
}


HRESULT STDMETHODCALLTYPE ProgramChangeTool::Init(IDirectMusicGraph *pGraph)
{
	return S_OK;
}

HRESULT STDMETHODCALLTYPE ProgramChangeTool::GetMsgDeliveryType(DWORD* pdwDeliveryType)
{
	*pdwDeliveryType = DMUS_PMSGF_TOOL_IMMEDIATE;
	return S_OK;
}


HRESULT STDMETHODCALLTYPE ProgramChangeTool::GetMediaTypeArraySize( DWORD* pdwNumElements )
{
	*pdwNumElements = 1;
	return S_OK;
}

HRESULT STDMETHODCALLTYPE ProgramChangeTool::GetMediaTypes( DWORD** padwMediaTypes, DWORD dwNumElements)
{
	(*padwMediaTypes)[0] = DMUS_PMSGT_PATCH;


	return S_OK;
}

Below is the code for inserting the tool into the graph:

	m_pProgChangeTool = new ProgramChangeTool();
	IDirectMusicGraph* pGraph;

	IDirectMusicAudioPath8* pDefaultAudioPath;
	m_pPerformance->GetDefaultAudioPath(&pDefaultAudioPath);
 
    HRESULT hr = pDefaultAudioPath->GetObjectInPath( 0, DMUS_PATH_PERFORMANCE_GRAPH, 0,GUID_NULL, 0, IID_IDirectMusicGraph, (LPVOID*) &pGraph );

	pGraph->InsertTool(m_pProgChangeTool, NULL, 0, 0);
	pGraph->Release();

//get instrument HRESULT hr = m_pCollection->GetInstrument( dwPatchNumber, &pInstrument);//download instrument to the port  hr = pPerformance->DownloadInstrument(pInstrument, pMsgNote->dwPChannel, &pDInstrument, NULL, 0, &pPort, &dwGrp, &dwMChannel);