Every night before he goes to sleep, veteran Canadian stage, film and television actor Kenneth Welsh (pictured) goes through lines from Dylan Thomas’ Under Milk Wood, of which he gives an astonishing one-man performance at Soulpepper this summer, following an acclaimed Luminato run last year. (It just won a Dora for sound design.) He goes through them chronologically, he claims, until he blacks out. Then, the next night, he picks up exactly where he left off.

The anecdote is an ideal entré to themes and incidents within Thomas’ masterful 1953 “play for voices,” which takes on the consciousnesses of dozens of inhabitants of a forgotten, fictional Welsh town called Llareggub (“Bugger all” backwards, proof of Thomas’ abiding love of the puerile possibilities within the Welsh language). This is a play, after all, about dreaming, opening with the characters’ subconscious iterations of their fantasies, and then following them through the arc of the day, and finally into evening and sleep again.

The main character of Under Milk Wood is the “Voice,” and Welsh is getting good practice for it by surrendering himself to it while drowsy. Indeed, Welsh and his director Ted Dykstra feel strongly that the Voice should not be a controlling, supercilious commentator. “The whole thing is a discovery,” notes Welsh. “[The Voice] creates these characters, but then recreates them out of some psychic connection he has with them. They’re never pasted on. They emerge from him.”

Welsh refers, then, to the kinds of magic that can occur onstage, where his actions, some of them improvised, are augmented by foley artists and musicians. (“The play was written for radio,” Welsh asserts, “and I wanted a radio up there with me.”) “The Reverend Eli Jenkins is a particular favourite,” he says, “because I base him on the man who really brought me to this play at the National Theatre School, [NTS co-founder] Powys Thomas. He played that role, and whenever I do it, Powys comes back to life in me. I actually have a lot of friends that I bring along.”

Then there’s the obvious, ghostly resonance of Welsh’s name: “My father always thought that its origin was the result of the many invasions by English kings of Ireland,” he says. “They would always hire these Welsh mercenary soldiers, taking them to Ireland to fight the Irish and just leaving them there. No one could pronounce their names so they just called them ‘Welsh.’ Welsh in Irish Gaelic actually means foreigner.”

The circumstantial perfection of this — an estranged Welshman taking on the entirety of Thomas’ play, an ode to the towns lost in Wales after World War II from the perspective of a voice initially ignorant of them — should not be overstated, for Welsh has studied Thomas’ text with the determination of a scholar his entire life.

“I always had this notion that I wanted to do it as a solo, as Thomas originally had done,” he says, “as this crazy person who comes out and becomes all these characters. I did it [privately] once, 25 years ago, and it worked. I felt then that one day it would reach the stage, somewhere. And now I’m doing it.” And so this Under Milk Wood is, even more than usual, a dream come true.