Thin as cling foil does not necessarily mean insubstantial, but Peter Gill’s engrossing production of Annie Baker’s 90-minute play (plus an interval) is certainly small and fairly quiet.

Ranged on four sides of a stony back patio of a coffee shop in Vermont, we eavesdrop on the ramblings of two 30-ish unemployed musicians, KJ (Ralf Little) and Jasper (Mackenzie Crook).

They are trespassers (and so are we) inside the fencing and behind the garbage cans, as righteously pointed out by 17 year-old nervous new boy Evan (Olly Alexander).

Evan’s still attending high school, and teaching at Jewish music camp. The other two recruit him to their chat about the music they played in a group called the Aliens, or the Limp Handshakes, or the Joseph Joszef… the songs sound wacky but good, and Jasper, who’s lately lost a girlfriend, is writing a novel in the slipstream of Henry Miller and Charles Bukowski.

It’s funny and touching, with a surprisingly lop-sided second act, a couple of good turns on the guitar, and a poetic sense of life passing through.

All three actors play with disarming intensity: dread-locked Little laid back, bony Crook fierce and unaccommodating, anxious Alexander keen to join in, mop-haired and sweetly boyish.

You could not imagine it all better done than it is. Lucy Osborne’s design is another corker, the music of Terry Davies perfect, and lighting of David Holmes (a great Fourth of July thump of fireworks) impeccable.