The phrase "a kind of impromptu" is correct and usable in written English.
It can be used to describe something that is spontaneous or unplanned, often in a creative or performance context.
Example: "The musicians decided to have a kind of impromptu jam session in the park, much to the delight of the passersby."
Alternatives: "a sort of spontaneous" or "a type of unplanned".
The housing may be drab, but the streets explode with a pageantry that makes every day a kind of impromptu Mardi Gras festival.
Functioning as a kind of impromptu public laboratory, play streets can demonstrate just how effective such spaces can be, and provide an argument for making such outlets — or something like them — permanent.
We followed some friends who were ahead down a road that ran along the seaside — beautiful snorkeling waters there — and found ourselves at a kind of impromptu front line.
During our earlier chat – which quickly devolved into a kind of impromptu therapy session, for reasons you might have picked up upon – Winfield-Chislett was quick to defend my dad for not showing me basic DIY skills.
Too young to drive and living in a town of pedestrian-free, lifeless streets, these teens staged a kind of impromptu protest against the automobile and had "some sense knocked into them".
Over the last two years, as his star has ascended, the group has traveled like a band on extended tour, tramping from Ecuador to Germany to Mexico to Colombia to Italy to France and now to New York, creating pieces in each place as a kind of impromptu performance.
It's a kind of street democracy, with impromptu public juries declaring their binding verdicts on how civic disputes should be resolved, refusing to allow the antagonists to leave until the group's judgment is enforced.
(Later in the scene, he would badly outmatch the latest British folk sensation, Donovan, laying down "It's All Over Now, Baby Blue" as a kind of response to Donovan's impromptu performance of his ditty "To Sing for You").
There's a lot of value that comes out of that, that kind of impromptu patient teaching of each other" Provider #28.
"We grew up going to all sorts of festivals," says Jazz. "Every year at Glastonbury, Dad would create this kind of impromptu camp where people would just gather.
He notes that startups with founders working by themselves at home or in their own office space are missing out on the kind of impromptu conversations that can happen when great minds come together — even if they're not all working on the same thing.
