Opening in London this week

THE REVIVAL
Observe the Sons of Ulster Marching Towards the Somme
Hampstead Theatre, NW3
Tuesday
Frank McGuinness established himself as a major-league playwright with this powerful and impassioned play when it was first performed at the old Hampstead Theatre in 1986. It follows eight Ulstermen who volunteer at the beginning of the First World War, and their unwitting journey from camaraderie to slaughter at the Battle of the Somme on 1 July, 1916.

THE FESTIVAL
Glastonbury 2009
Friday
Wellies may not be needed this year, as the sun promises to shine on a quite magnificent line-up. Starting things off are Neil Young, Lily Allen and Fleet Foxes, while Bruce Springsteen headlines the festival on Saturday. Blur, having kissed and made up, play out proceedings on Sunday evening.

THE EXHIBITION
Walking in My Mind
Hayward Gallery, SE1
Tuesday
Large-scale sculptures and installations by 10 international artists who aim to visualise the inner workings of the artist's imagination offer nightmare room sets that appear covered in cobwebs and something like a studio set for the Teletubbies. Could be mindblowing or just maddening.