Hi again WAV. Are you familiar with Liverpudlian history, particularly the development of the distinctive accent? I think you'll find that the blues singers of the Mississippi Delta were in fact scousers to a man. If you study the linguistics of Liverpool, you will hear the words 'this, that, them and those' prounced as 'dis, dat, dem and dose'. This was largely as a result of poor adenoidal care in the Liverpool hospitals, but it appears to have travelled the Atlantic and become embedded in the accents of the older blues singers; for instance, you would never hear a proper bluesman saying 'that' when he meant 'dat'. As for the Beatles, I was a teenager at the time (you were an infant) and I never heard the Beatles affect any accent than Scouse (apart from Paul, who would occasionally try to talk posh to impress Jane Asher).