So why did 'Ain't it a shame' in the USA become 'Ain't that a shame' in the UK a few months later? I can see that Pat Boone allegedly wanted to make it 'Isn't it a shame', bless 'im, but can't see a ready explanation to the changing of it.
‘Blueberry Hill’, Fats’ sixteenth million-seller, was his biggest hit and rose to No.2 in America and No.6 in the UK in December 1956. So great was its impact in Britain that Fats’ 1955 hit ‘Ain’t That A Shame’ rose to No.23 in January 1957 over a year after it’s release. Back in those days records remained in the catalogue for a long time, so it was not a re-release.