" If you wanted to sing at his club you had to convince him that your song was relevant to YOUR background and origins , while HE sang songs from Scotland , Lancashire , Yorkshire or whereever"

Where the hell did this come from???
I was a regular at the Singers Club for over 20 years and more than often cringed at some of the singers who turned up casually.
The Club policy - IE - the type of singer who was booked as GUEST - was decided on by an audience committee and by ALL the residents of the club.
MacColl's view, along with that of Alan Lomax Bert Lloyd and all the people that brought the club (and the revival) into being, was that it was important to explore your own national repertoire rather than all try to sound like Guthrie, Leadbelly, Broonzie and the other American artists who were influencing the scene in the early days. The end result was a blossoming of the British and Irish reperoires. I saw The Stewarts, Joe Heaney, Walter Pardon, Doc Watson, Seamus Ennis, Paddy Tunney, Bobby Casey, and scores more traditional performers at the Singers Club - they were always given a great welcome and they were all perfectly comfortable performing there (except on the night Harry Cox had to take his new false teeth out because they were affecting his singing!)
The club policy was that the songs performed there by the residents or by the booked guests should be traditional or traditionally influenced and that it should be performed to a reasonable standard - they (and I) had no time for the 'near enough for folk' school of thought that once (and still, to some extent) permeates the folk scene. It wasn't, and didn't pretend to be a singaround club and you invariably came a way with a night of good songs well sung under your belt. Ewan and Peggy always played to a packed house.
Would that there were more clubs with policy and standards today.

PS
I agree totally that Stalin's policied were loathsome (though, as Ifor has well pointed out, he managed to fool a lot of the people a lot of the time). But I have problems in deciding whether those policies are any more loathsome than those of a country that has persistently armed and financed some of the worst tyrants in history (including Saddam Hussain), has dropped bombs on more than 50 countries since the end of WW2, has invaded numerous (usually poor, 3rd world) countries, has used chemical weapons such as napalm, agent orange and phospherous on civilians, has interfered with the internal politics of scores of countries throughout the world and has helped overthrow democratically elected leaders (and helped rig their own presidential election). This (unnamed) country is at present illegally holding prisoners without charge and subjecting them to abuse and torture - I suppose one man's monster is another man's cuddly toy.
PPS Where was MacColl after he deserted - do I sense another urban legend in the making?