"I've criticized MacColl's floating accent on here before"
MacColl was from a Scots family - his accent varied at home as it did with his singing.
I've sat in the middle of conversations with him and his mother Betsy and thought (in those days) that I may as well have been sitting in a Greek Cypriot Cafe in Camden Town (my local eatery in those days).
His accent broadened when in Scots company - it was the one he was used to at home.
I always felt that he deliberately neutralised Scots texts (as an actor does) to make them more accessible.
Just before I moved to London a few of us went to the Edinburgh Festival Fringe and saw MacBeth (complete with the witches in skimpy see-through robes).
Matt McGinn played the part of the gatekeeper - didn't understand a bloody word - and my dad was born in Glasgow!
"using voice as an instrument"
Fine, as long as you remember that British folk song is word and not music based and English and Scots songs are strongly narrative.
Over-instrumentation and, on occasion, over-musicality, can interfere with the communication of this.
This is my problem with electric-folk - it exorcises the narrative and becomes something else.
Jim Carroll