We also gave an hour's long talk on him and were able to set p a mini-singing workshop for inexperienced singers in order to demonstrate how The Critics Group method worked
Do you think this method was exclusively developed by MaCcoll, or derived from prior collaboration with Joan Littlewood?

An insight below:

https://www.bl.uk/20th-century-literature/articles/an-introduction-to-joan-littlewoods-theatre-practice