*rubs hands with glee* Oooh, a classical music recommendation! How "old school" is your Aunty Eve? You mentioned Beethoven and Mozart, both of whom were late 1700s - early 1800s (in Beethoven's case). Personally, I adore Bach, but he's later, mid-to-late 1800s. (Mmmmmm, Glenn Gould's "Goldberg Variations"... *swoons*)

I agree with the poster about Handel, but I'd pick something other than "The Messiah" simply because it's so popular--your aunty might already have it, though a different recording of it would be good, too. (Now we're slipping into real classical buff territory, the merits of this recording over that!)

I quite like Scarlatti, if your aunty is into the Italians circa 1700. :-) There's really so much to choose from!