What is "lah-di-dah"

a. (context British pejorative English) Of or from the upper class of society. interj. 1 (context US English) not a care in the world ''(used in a sing-song voice, for childhood rhymes)'' 2 (context US English) Frequently heard in New Orleans, uttered by revelers in resorts of drink and music ''(used in a mildly pejorative sense, dismissing, for example, a man dressed in yellow bicycling Spandex with a silly walk, as Well, lah-di-dah. Also a term interjected when politicians waffle. Hmm. Sounds pretty lah-di-dah to me!)''

Lah-Di-Dah is a compilation album by Jake Thackray, released by EMI on LP and CD (with bonus tracks) in 1991.