if it does not make sense Jim, try this ,i was referring to joseph taylor a singer who entered in competions, since he entered in competitions his situation was different from say walter pardon.
the OP is in a folk revival situation she is asking about a folk voice , not about nervousness of trad singers, my post makes absolute sense. here it is again in a REVIVAL CONTEXT
   Jim,TRADTIONAL SINGERS unlike folk song singers in clubs, did not have to do 40 minute spots in folk clubs, so for example. .I try to sing naturally,however I have to give some thought to planned changes of keys for one song after another [something that a trad singer did not have to do]
I think it is reasonable advice to say that if a singer wants to use a folk voice for 40 minutes at a time , that good breathing technique, plus thought about using different keys, as well as singing natrually enters in to the equation.
Finally, the OP is in a revival situation. the oOP does not state that she wants to sing like a tradtional singer she talks about a folk voice , this could mean a folk revival voice , you choose to interpret it as singing like a tradtional singer, I interpret as a meaning in a folk revival voice, but not a classical voice, or opera voice or jazz voice , Do you understand that?