One of those things about growing up a bit pikey in the part of the UK that speaks a dialect that only resembles English to someone who's had an ear candling mishap is that you spend a life being corrected on pronunciation and other little details. Don't you mean?, they'll say, pedantically. As a child, I learned most everything from books so pronunciation often had to be guessed at using the peculiarly tuned phonetics of the region. It wasn't like I could ask my mum how to pronounce 'Achilles' or 'diplodocus' or somesuch and it was before the time you could hit a button and have the computer tell you. Or 'chorizo,' though that had yet to become a menu item, the most exotic thing in the early 1980's East Midlands still came in a box labelled Vesta (not that I was allowed, as it would 'make the house smell', presumably of something other than cigarette smoke and perpetual overcooking, the madeleines of my childhood).
People still do it today, especially with foreign words (and I think often they're making them up, or adding that signature English theatrical flourish). Generally, I smile tolerantly, wait till they turn their backs and murder them. OK, I wouldn't have have done the 'E B minor' – though all I remember from music lessons at my school was the xylophone didn't have a full complement of keys and the C was quite an important omission – but mostly because I used to attempt to play the guitar (I suspect less down to a deep, abiding love for music, but more because my misguided brain thought a series of badly played chords would somehow feature as an aphrodisiac for female company, but anyway, I could play all the notes flat).