There really are different ways of using the voice, it's not just a question of lacking the technique.

It's the same way that a fiddle playing in a folk tradition is essentially a different instrument from a violin being played classically. The very things that a clasasical violinist will have learned to avoid may be an essential part of a traditional way of playing.

So what classically trained singers may hear as failure to use the voice right - a head voice rather than an open voice - may be a very important element in a traditional singer's technique.

Learning how to avoid hurting your voice is useful - but someone who sings for the pleasure of it in a small setting isn't making the same demands on the vocal mechanisms as a professional trying to achieve a maximum volume.

Opera sounds best with classically trained singers, I think - but I don't find that true for folk songs - including classical arrangements. Vaughan Williams arrangements of "Linden Lea" (which is a dialect poem by William Barnes t=rather than a folk song)for example sounds just wrong to me when I've heard it sung by concert singers. But Dave Goulder's singing of it (on a CD "Stone, Steam and Starlings" Harbourtown Records, HARCD 017) I think is very powerful and moving.

Incidentally, "Linden Lea" doesn't seem to be in the DT. So here is a link to a midi of the tune used by Vaughan Williams and here is a link to the words of William Barnes's poem, in broad Dorset (since Dick Greenhaus rightly pointed out the other day on a thread somewhere it is discourteous mentioning a song without putting the words in).