"impromptu stage" is a correct and usable phrase in written English
It is generally used to refer to an area or platform that has been quickly and unexpectedly set up for a performance. For example: "The crowd was surprised when the band jumped out of the crowd and took their places on an impromptu stage that had been set up in the middle of the plaza."
On-stage anger Babyshambles Singer Pete Doherty once fled a gig and refused to play after a fan gave him a wedgie during an impromptu stage dive.
As I strode on to the impromptu stage, I became aware of the crumhorn music slowing down and dropping in pitch.
One guest began skinny-dipping in the pool at 6 a.m. one day, and the pergola's picnic table has been an impromptu stage more than once.
Although its star, Fred Astaire, can light up a Times Square arcade on his own power or turn Central Park into an impromptu stage for romance beneath a soundstage moon, the performer he plays is a has-been version of himself: middle-aged and prickly, with weariness threatening to overtake his ever-longer face.
There, we washed down perfectly cooked sea bream and spinach (£15) with bottles of Cairngorm Gold and peppery pinot noir, and settled in for the night as fiddles, guitars, drums and a double bass squeezed past us to an impromptu stage.
Add that it was the final weekend of the show's 12-year Broadway run, and that these fans had won an online video contest to attend a party at the Life Café in the East Village, where that famous Act 1 scene is set, and it was little wonder that about midnight Friday, the fans spontaneously pushed the cafe's tables together, creating an impromptu stage.
I stood in front of one of the many impromptu stages – stood isn't quite right.
It's a concert pianist, Bing & Ruth, who last year impromptu staged his set right by the canyon, and anyone who experienced it loved it.
It was here on these impromptu stages at the Harold Washington Library's YouMedia Center, Columbia College and elsewhere, under the tutelage of such community builders as the late "Brother Mike" Hawkins and Kevin Coval, that he found his voice, and attended workshops that helped him record his music — music that is now transforming contemporary hip-hop.
Just inside the Sherman Avenue Community Garden, the finishing touches are being put on the impromptu wood stage that has just gone up.
And soon more than 30 members of the Opera Company of Philadelphia chorus were singing, dancing and toasting one another with coffee and soda cups, as the soloists turned the cheese steak stand into an impromptu opera stage.
