Back to Betsy's original question. I notice that the festivals she mentions are all in Yorkshire so maybe it's a local phenomenon. The festivals I know in Soutehrn England - Towersey, Chippenham, Tenterden, Fareham & Gosport, doing Wadebridge this year - all have musicians' sessions programmed in some of which we in Spare Parts help to run. We do run them as "tunearounds" because we think it is fairer on the less experienced who may be brilliant in the safety of their own kitchens but find the cut and thrust of a spontaneous session a bit intimidating.