At last, the Young Vic has come of age. Fun Home marks one of the best productions it has housed, and breaks new ground for musical theatre.

Fun Home charts the real life steady progress towards coming out of tomboy-to-confident-lesbian cartoonist Alison Bechdel which coincides with the day her secretly-gay funeral director father stepped into the path of an oncoming truck.

Carrying such brutal material needs a mature and sophisticated treatment and both the score and the script in Jeanine Tesori and Lisa Kron’s collaboration rise magnificently to the occasion.

Distilled from its 2015 Broadway outing, Sam Gold’s production is fluid, and tender, and beautifully lit and designed. It proves the perfect framework for a shining cast – Kaisa Hammarlund taut, observant, and powerful as the adult Alison, with Eleanor Kane and Brooke Haynes (on press night) superbly sharing the role of her younger selves. Haynes is a star to be, Kane equally on the brink: her solo ‘I’m Changing My Major to Joan’ just one highlight among so many in the show.

As its still centre, and Alison’s mother, Jenna Russell has the most demanding role, contained within her cloak of regret and pain, releasing it into a powerfully angry ‘Days and Days’.  The extreme quality of Zubin Varla’s performance as Alison’s father Bruce is that it’s almost too uncomfortable to watch.

Songs grow from the narrative line – they don’t fit any known Broadway pattern, and this complexity keeps you more engaged with the story and characters.

In 2015 Fun Home claimed to be the first musical to feature a lesbian lead. Even if Wicked and The Color Purple have gay women characters, nothing before has placed them so fundamentally at the centre of the stage and the plot, and with such technical clarity and emotional truth.

The stage of the Young Vic seems to have been extravagantly enlarged. Or maybe it’s just the huge pulsing heart of this excellent production gives that impression.

Did I mention three kids do a dance number on a coffin? What’s not to love?

until 1 September