Seeing this made me realise I'd not heard about Gjerstad for a while, he used to be a regular visitor to the UK.
Just checked his Bandcamp and he's still releasing which is good to see. Time to catch up on some recent releases
The Gil Evans Orchestra - Into The Hot [Impulse/Sparton, Canada 1962 mono]
Such a strange release, I wonder how many Evans fans felt hoodwinked in 1962
Stan Kenton - City Of Glass [Capitol Records, UK 10" 1952]
preceded by
Earl Bostic - Jazz As I Feel it [King Records, USA 1963]
with thanks to @JSngryfor prompting the Bostic purchase
They'd certainly be arrested and get lifetime bans for an equivalent action in a UK sports stadium, football, cricket or whichever sport.
How much would they have paid for their tickets that close to the field?