@Guest Hootenanny.
The clip I posted on the folk music thread has a conversation where one of the Clancy Bros. makes the point that they started as actors and they had no qualms altering words in order to better communicate with their audience. They were insistent that communication was the key to success.
    This has some remarkable parallels with Ewan Macoll and more especially Joan Littlewood, whom he married in 1936. Littlewood created a radio documentary in 1939The Classic Soil using local voices/accents. This was followed post war in Stratford with a series of plays...http://essentialdrama.com/practitioners/joan-littlewood/
I would argue these influences fed through into the creation of the radio ballads (Groundbreaking radio programs) For Littlewood all this culminated in "Oh What Lovely war" that some argue has classic agiprop influences. It seems to me it is very difficult to separate the two entities from their bodies of work. I would argue they both fed off each other and the influences remained throughout their subsequent careers.
In a nutshell: The living soil predated the radio ballads. The workers Theatre Movement to the Theatre of Action long preceded Oh what a lovelty war.

As a total aside Joan Littleqwood played a major part in establishing the career of Brendan Behan. The above is a bit of a gross simplification but I find their interaction and influence on one another fascinating, as I cannot see where one finishes and the other starts. I do not think a discussion of Ewan Maccoll can be complete without bringing Joan Littlewood into the conversation.

Do you see a parallel here?
The Theatre Workshop's work reflected the ideas Littlewood was constantly developing. In addition to regular rehearsals for their various productions, the actors trained vigorously. Their days began with movement—a series of rigorous exercises based on Rudolph Laban's concept of the "human effort cube." This was followed by a period of vocal training and then by text and character work incorporating the theories Constantin Stanislavski set out in his book An Actor Prepares but adapted and extended into improvisation and theater games. From a later perspective, it is almost impossible to imagine how revolutionary Littlewood's teaching and directing methods seemed in England in the 1940s. Littlewood preferred to work with actors who were enthusiastic but previously untrained because they were largely unstructured, instinctive and highly individual, and not afraid to risk making fools of themselves. She ran weekend schools and summer workshops—most notably at Ormesby Hall, a grand mansion and garden in Yorkshire—from which she often garnered young recruits, molding them into the ensemble. She worked intensively and in great detail, believing that "the smallest contact between characters in a remote corner of the stage must become objectively true and relevant." One actor recalls, "She'd have all these ideas, more in an hour than I could think of in a lifetime." Said another, "We had intense emotional scenes very often … but I found Littlewood the most stimulating person to work with, the most co-operative person. She drew out whatever talent you had."