My Mum and Dad were born in pretty much the heart of Brum, Belmont Row and King Edwards Road, so I had a Brum accent. However we moved to Langley near Oldbury around October 1945, and the boys at school poked fun at my accent, and I found some things hard to understand.
Years later having now acquired a mixture of Brum and Black Country I used to go down to Old Hill where Tom Sommerton the Vincent man had a bike sales and workshop.
The people around there, only about a couple of miles or so away, spoke yet another language, a mixture of Black Country and Old English. I found it very hard to understand at times.