Wiktionary
alt. (non-gloss definition: Nonsense word traditional to English ballads and madrigals.) interj. (non-gloss definition: Nonsense word traditional to English ballads and madrigals.) n. 1 (alternative form of folderol English) 2 A gaudy thing of little value; a trinket. 3 nonsense. 4 Excessive efforts expended on a something trivial; much ado about nothing.
Wikipedia
Fol-de-Rol is a prime-time family variety special in the USA that was set at a medieval fair, produced by Sid and Marty Krofft and based on their 1968 live puppet show. It was broadcast by ABC on February 27, 1972. It was directed by Tony Charmoli and scripted by David Robison, Les Pine, Jerry Mayer and Dennis Kleinhole.
Usage examples of "fol-de-rol".
Somehow, every time the magic of fol-de-rol tried conclusions with the magic of science, the magic of fol-de-rol got left.
Whenever I travel aboard a plane except when on holiday -- which is about once every five years -- I hand the stewardess a small sealed envelope for transmission to the plane's captain and the captain, usually as anxious as the next man to impress a pretty girl, generally divulges the contents to her, which is a lot of fol-de-rol about complete priority under all circumstances and invariably wholly unnecessary except that it ensures one of impeccable and immediate lunch, dinner and bar service.
All this damned fol-de-rol about smashing up radio transmitters and making us think that we were the only craft left with a transmitter.
The acts and scenes of the piece--one of those singularly witless compositions which have at the least the merit of giving entire relief to an audience engaged in mental action or business excitements and cares during the day, as it makes not the slightest call on either the moral, emotional, esthetic or spiritual nature--a piece in which among other characters, so called, a Yankee--certainly such a one as was never seen, or at least like it ever seen in North America, is introduced in England, with a varied fol-de-rol of talk, plot, scenery, and such phantasmagoria as goes to make up a modern popular drama--had progressed perhaps through a couple of its acts, when, in the midst of this comedy, or tragedy, or non-such, or whatever it is to be called, and to offset it, or finish it out, as if in Nature's and the Great Muse's mockery of these poor mimics, comes .