Kick for Touch/ Small Change/ Mean Tears, Crucible Theatre, Sheffield

Peter Gill is one of this country's most revered directors and theatrical gurus. He blossomed at the Royal Court in the Sixties, where his revivals established D H Lawrence as a playwright of genius, and he went on to found the Riverside Studios and the influential National Theatre Studio. He is equally gifted as a dramatist, but his plays have been described as "one of the best-kept secrets of the British theatre".

Masterminded by Michael Grandage, this boldly imaginative season at the Sheffield Crucible aims to share the deep pleasure of Gill's drama with a wider audience. It is all the more admirable for two reasons. It was planned long before his recent play The York Realist proved such an unexpected hit in London earlier this year. And it dispels any whiff of necrophilia by presenting Gill as a creative work in progress. A retrospective of four earlier pieces is programmed alongside the main house premiere of his new play, Original Sin, a reworking of the "Lulu" legend, with a boy as the lust-object.

The season has begun with three of the revivals. The best of these pieces – Small Change (1976) and Kick for Touch (1983) – are rooted in Gill's imaginative homeland. This is Catholic, working-class Wales where the poverty is so bad you have to hide from the rent man. The theme of gifted sons who struggle to extricate themselves from the apron strings of mothers might lead you to expect a reverent rerun of Lawrence, with the addition of an equally agonised bond between brothers or male childhood friends. But these immaculately cast and beautifully nuanced productions – directed respectively by Rufus Norris and Josie Rourke – are powerful eye-openers to Gill's breathtaking audacity with form and dialogue.

The plays jettison the regularities of linear plot as firmly as they junk the bric-a-brac of realistic scenery. In this starkly poetic stage language, the simple tilting of a face in a different direction, or re-angling of a chair, can effect an instantaneous relocation in time or place. As the characters fight with their psychic inheritance, Gill's dramaturgy shows how the past remains inescapably active in our lives, through the use of a kind of fierce temporal flickering that feels like an edgy, yet somehow continuous, present tense. Without ever losing its ring of authentic vernacular, the dialogue, too, is heightened in expressiveness, through the motif-like echoing of phrases, woven together in the manner of a musical score.

Matt Bardock and Justin Salinger superbly communicate the tangle of estrangement and stifling closeness between brothers in Kick for Touch, a childhood trauma at once disuniting them as a family and leaving them hopelessly bound together. Unequal love is dramatised through the unfinished business of two childhood friends (the excellent James Loye and Damian O'Hare) in Small Change, and through the running-sore wranglings of a middle-aged writer and his self-obsessed, chronically irresolute bisexual boyfriend (given spot-on performances by Christopher Fulford and Stephen Billington) in Paul Miller's revival of the 1987 play Mean Tears.

This last, with its metropolitan setting, is my least favourite. Repetitive in his ineffectual denunciations of the slippery lover, the writer figure comes across as an over-wordy exercise in self-pity and esprit d'escalier. The plays about the Welsh working class seem drawn from a deeper well, and contain images that will haunt you for the rest of your life: the infinitely touching sight, say, of the two very different mothers in Small Change (the lovely Susan Brown and Maureen Beattie) humming and dancing together in their pinnies – a moment of shy, spontaneous and fragile truancy from the difficult daily grind that will lead one of them to early suicide.

In the words of the playwright Nicholas Wright, a Peter Gill season is "one of the best producing ideas in years". It's further proof, too, of why the Crucible deserves its accolade as the Theatrical Management Association regional theatre of the year.

To 22 June (0114-249 6000)