diff --git a/dlls/dmusic/clock.c b/dlls/dmusic/clock.c
index c54992c24a0..4d9a1b40454 100644
--- a/dlls/dmusic/clock.c
+++ b/dlls/dmusic/clock.c
@@ -1,4 +1,5 @@
-/* IReferenceClock Implementation
+/*
+ * IReferenceClock Implementation
  *
  * Copyright (C) 2003-2004 Rok Mandeljc
  *
@@ -21,9 +22,15 @@
 
 WINE_DEFAULT_DEBUG_CHANNEL(dmusic);
 
+static inline IReferenceClockImpl *impl_from_IReferenceClock(IReferenceClock *iface)
+{
+    return CONTAINING_RECORD(iface, IReferenceClockImpl, IReferenceClock_iface);
+}
+
 /* IReferenceClockImpl IUnknown part: */
-static HRESULT WINAPI IReferenceClockImpl_QueryInterface (IReferenceClock *iface, REFIID riid, LPVOID *ppobj) {
-	IReferenceClockImpl *This = (IReferenceClockImpl *)iface;
+static HRESULT WINAPI IReferenceClockImpl_QueryInterface(IReferenceClock *iface, REFIID riid, LPVOID *ppobj)
+{
+	IReferenceClockImpl *This = impl_from_IReferenceClock(iface);
 	TRACE("(%p, %s, %p)\n", This, debugstr_dmguid(riid), ppobj);
 
 	if (IsEqualIID (riid, &IID_IUnknown) || 
@@ -36,8 +43,9 @@ static HRESULT WINAPI IReferenceClockImpl_QueryInterface (IReferenceClock *iface
 	return E_NOINTERFACE;
 }
 
-static ULONG WINAPI IReferenceClockImpl_AddRef (IReferenceClock *iface) {
-	IReferenceClockImpl *This = (IReferenceClockImpl *)iface;
+static ULONG WINAPI IReferenceClockImpl_AddRef(IReferenceClock *iface)
+{
+	IReferenceClockImpl *This = impl_from_IReferenceClock(iface);
 	ULONG refCount = InterlockedIncrement(&This->ref);
 
 	TRACE("(%p)->(ref before=%u)\n", This, refCount - 1);
@@ -47,8 +55,9 @@ static ULONG WINAPI IReferenceClockImpl_AddRef (IReferenceClock *iface) {
 	return refCount;
 }
 
-static ULONG WINAPI IReferenceClockImpl_Release (IReferenceClock *iface) {
-	IReferenceClockImpl *This = (IReferenceClockImpl *)iface;
+static ULONG WINAPI IReferenceClockImpl_Release(IReferenceClock *iface)
+{
+	IReferenceClockImpl *This = impl_from_IReferenceClock(iface);
 	ULONG refCount = InterlockedDecrement(&This->ref);
 
 	TRACE("(%p)->(ref before=%u)\n", This, refCount + 1);
@@ -63,29 +72,42 @@ static ULONG WINAPI IReferenceClockImpl_Release (IReferenceClock *iface) {
 }
 
 /* IReferenceClockImpl IReferenceClock part: */
-static HRESULT WINAPI IReferenceClockImpl_GetTime (IReferenceClock *iface, REFERENCE_TIME* pTime) {
-	IReferenceClockImpl *This = (IReferenceClockImpl *)iface;
-	TRACE("(%p, %p)\n", This, pTime);
-	*pTime = This->rtTime;
-	return S_OK;
+static HRESULT WINAPI IReferenceClockImpl_GetTime(IReferenceClock *iface, REFERENCE_TIME* pTime)
+{
+    IReferenceClockImpl *This = impl_from_IReferenceClock(iface);
+
+    TRACE("(%p)->(%p)\n", This, pTime);
+
+    *pTime = This->rtTime;
+
+    return S_OK;
 }
 
-static HRESULT WINAPI IReferenceClockImpl_AdviseTime (IReferenceClock *iface, REFERENCE_TIME baseTime, REFERENCE_TIME streamTime, HANDLE hEvent, DWORD* pdwAdviseCookie) {
-	IReferenceClockImpl *This = (IReferenceClockImpl *)iface;
-	FIXME("(%p, 0x%s, 0x%s, %p, %p): stub\n", This, wine_dbgstr_longlong(baseTime), wine_dbgstr_longlong(streamTime), hEvent, pdwAdviseCookie);
-	return S_OK;
+static HRESULT WINAPI IReferenceClockImpl_AdviseTime(IReferenceClock *iface, REFERENCE_TIME baseTime, REFERENCE_TIME streamTime, HANDLE hEvent, DWORD* pdwAdviseCookie)
+{
+    IReferenceClockImpl *This = impl_from_IReferenceClock(iface);
+
+    FIXME("(%p)->(0x%s, 0x%s, %p, %p): stub\n", This, wine_dbgstr_longlong(baseTime), wine_dbgstr_longlong(streamTime), hEvent, pdwAdviseCookie);
+
+    return S_OK;
 }
 
-static HRESULT WINAPI IReferenceClockImpl_AdvisePeriodic (IReferenceClock *iface, REFERENCE_TIME startTime, REFERENCE_TIME periodTime, HANDLE hSemaphore, DWORD* pdwAdviseCookie) {
-	IReferenceClockImpl *This = (IReferenceClockImpl *)iface;
-	FIXME("(%p, 0x%s, 0x%s, %p, %p): stub\n", This, wine_dbgstr_longlong(startTime), wine_dbgstr_longlong(periodTime), hSemaphore, pdwAdviseCookie);
-	return S_OK;
+static HRESULT WINAPI IReferenceClockImpl_AdvisePeriodic(IReferenceClock *iface, REFERENCE_TIME startTime, REFERENCE_TIME periodTime, HANDLE hSemaphore, DWORD* pdwAdviseCookie)
+{
+    IReferenceClockImpl *This = impl_from_IReferenceClock(iface);
+
+    FIXME("(%p)->(0x%s, 0x%s, %p, %p): stub\n", This, wine_dbgstr_longlong(startTime), wine_dbgstr_longlong(periodTime), hSemaphore, pdwAdviseCookie);
+
+    return S_OK;
 }
 
-static HRESULT WINAPI IReferenceClockImpl_Unadvise (IReferenceClock *iface, DWORD dwAdviseCookie) {
-	IReferenceClockImpl *This = (IReferenceClockImpl *)iface;
-	FIXME("(%p, %d): stub\n", This, dwAdviseCookie);
-	return S_OK;
+static HRESULT WINAPI IReferenceClockImpl_Unadvise(IReferenceClock *iface, DWORD dwAdviseCookie)
+{
+    IReferenceClockImpl *This = impl_from_IReferenceClock(iface);
+
+    FIXME("(%p)->(%d): stub\n", This, dwAdviseCookie);
+
+    return S_OK;
 }
 
 static const IReferenceClockVtbl ReferenceClock_Vtbl = {
@@ -111,8 +133,8 @@ HRESULT DMUSIC_CreateReferenceClockImpl(LPCGUID riid, LPVOID* ret_iface, LPUNKNO
         return E_OUTOFMEMORY;
     }
 
-    clock->lpVtbl = &ReferenceClock_Vtbl;
-    clock->ref = 0; /* will be inited by QueryInterface */
+    clock->IReferenceClock_iface.lpVtbl = &ReferenceClock_Vtbl;
+    clock->ref = 0; /* Will be inited by QueryInterface */
     clock->rtTime = 0;
     clock->pClockInfo.dwSize = sizeof (DMUS_CLOCKINFO);
 
diff --git a/dlls/dmusic/dmusic_private.h b/dlls/dmusic/dmusic_private.h
index 4f2247e79d1..3cfffba58aa 100644
--- a/dlls/dmusic/dmusic_private.h
+++ b/dlls/dmusic/dmusic_private.h
@@ -166,13 +166,13 @@ extern HRESULT DMUSIC_CreateDirectMusicPortImpl (LPCGUID lpcGUID, LPVOID *ppobj,
  * IReferenceClockImpl implementation structure
  */
 struct IReferenceClockImpl {
-  /* IUnknown fields */
-  const IReferenceClockVtbl *lpVtbl;
-  LONG           ref;
+    /* IUnknown fields */
+    IReferenceClock IReferenceClock_iface;
+    LONG ref;
 
-  /* IReferenceClockImpl fields */
-  REFERENCE_TIME rtTime;
-  DMUS_CLOCKINFO pClockInfo;
+    /* IReferenceClockImpl fields */
+    REFERENCE_TIME rtTime;
+    DMUS_CLOCKINFO pClockInfo;
 };
 
 typedef struct _DMUS_PRIVATE_INSTRUMENT_ENTRY {