Not only is it a play of great appeal to adult audiences, but now, clinchingly, it is included in the Higher drama curriculum as an example of contemporary Scottish drama.
The double opportunity has been seized to some purpose. Co-production with Dundee Rep has shared the cost and also given TAG a major theatre to open its tour. Sponsorship from Sainsbury's pays for a programme to keep in the book cupboard and educational back-up impressive even by TAG's own standards.
TAG is the first Scottish company to get support from Sainsbury's new regional arts sponsorship scheme.
One of its benefits is that a resource pack for Standard and Higher grade drama, and TAG's extensive education programme - which includes theatre-based workshops, teachers' in-service sessions, director's talks and workshops in schools - come free to schools.
Produced first in 1947 by the radical Unity Theatre and then forgotten, the play - about 1930s tenement life from a woman's point of view - was memorably revived in an "oldies" programme in 1982, when Giles Havergal dazzled everyone by giving it the same epic treatment he had recently given to Sean O'Casey.
After a successful transfer to London, it was in danger of disappearing under its own mythology, so TAG's production is timely. Typically level-eyed and sincere in his interpretation, Graham gives it simple staging, neither cramping it in a box set nor imposing a cosmic vision.
In fact, the only counterpoint to the largely monochrome text is lyrical, with Dennis Potter-style inserts of popular music giving the talented Pauline Knowles the chance to sing, and at the same time gesture at a depth of character that the play's stereotypes generally miss.
Most of the characters are out of stock, but the great virtue of the play is that the Unity Theatre for once commissioned a woman writer to mix them. It is easy to suggest that the playwright identified with Maggie, like herself a middle-aged wife and mother, because this almost saintly, urban Earth Mother speaks with surprising honesty of a woman's lot in her generation.
Unfortunately, the original play was partially rewritten for the 1982 revival - but it remains typical of its genre, with its relentless detailed portrayal of the squalor of slum life and of the evils of unemployment and poverty. There's even a character called Bertie who dies of tuberculosis (there was always TB in Unity plays).
Perhaps one day a director will rescue the original version, an important document from a significant popular theatre movement, and restore this milestone in theatre history.
Tramway, Glasgow, tel: 0141 287 3900 until October 19 Aberdeen Arts Centre, tel: 01224 641122, October 22-26 Traverse Theatre, Edinburgh, tel: 0131 228 1404, October 30-November 3 Ryan Centre, Stranraer, tel: 01776 703535, November 5 Theatre Royal, Dumfries, tel: 01387 253383, November 7-9
For details of the education programme, tel: 0141 429 2877