Dear Sipowicz,
By this "dad" or "da'" thing I mean that the original song word was "dad" with the N. England hard "a" sound. Calling father da' with the soft a like daaaa , in Liverpool at least, da' is (or was) typical of Irish decent. So a Livepool-Irish person would talk of "me da'" rather than "me dad". It's a small point compared with "row". No racialism here, by blood I'm half English and half Irish - nationality English. Many SE Eglanders may like da' as they like their long, soft "a"'s - they take a barth rather than a bath, lol.
Long time making small point, sorry.
SIQ.