I suspect that this thread might have been started in response to something I said.
Can I make it clear that I don't believe that traditional singers in general fared badly at the hands of us outsider. As a rule the behaviour towards these elderly singers was usually, in my experience, exemplary.
However, bringing singers into an environment to which they were not used did on occasion cause problems and required a degree of sensitivity and thoughtfulness which sometimes was not forthcoming.
Walter Pardon was a tolerant, easy going man who never complained, but I know he dropped at least two songs from his repertoire because of audiences who dragged down the speed of his choruses, thus forcing him to do the same. Other singers have been thrown by audiences harmonising on choruses (and on occasion by those who have insisted on joining in on the verses, whether they have been invited to do so or not). God knows what Walter and his contemporaries would have made of the eejits who find it amusing to 'pop their cheeks' on certain songs.
I've described elsewhere the experience of the elderly Irish flute player at the hands of one set of club organisers (an incident the Cap'n shrugged off by telling us how good he (the Cap'n) is to guests).
Take a simple thing like accommodation for those away from home.
There was a debate at one time in Folk Review about elderly singers who, after a hard nights singing, were then treated to 'a party' consisting of half of the people who had attended the club being invited back to where the guest was being put up for the night. In a couple of cases cited, after another couple of hours singing, the guest was then offered a piece of floor and a sleeping bag. This happened only once in my experience, but I have heard of it happening elsewhere.
On the question of payment; we were once asked to bring one of the singers we were recording to a festival and were horrified to learn on arrival that the organisers only paid the performers' expenses as it was thought good for their reputations to appear there. We had to insist, with some argument, that the singer be paid and we made up the rest of his fee by giving him our expenses.
We've discussed ad nauseum (the 'useful') Peter Kennedy's attitude to paying his singers, issuing recordings without asking or telling the performer, getting them to sign contracts which (supposedly) passed over the rights of their songs and music to him, then demanding royalties from revival singers who wished to record them, dubbing accompaniments onto field recordings, publishing other collectors work without permission…… etc, so there's no need to go there again!
Ireland has had her Kennedy-clones in the more recent past.
One record company launched a series of LPs of traditional singers, having paid them the grand sum of – a bottle of whisky each.
More recently, a Kerry broadcaster presented a series of radio programmes on folklore, song, story, music and oral history, for which none of the participants were paid, but were only too pleased to be on the radio. When the series finished, the broadcaster, without asking his informants, assembled the programmes into an attractively presented package and offered them for sale, mainly to libraries and educational establishments, at €3000.00 a set.
Probably the most poignant example of a singer not being appreciated for his contribution to traditional music was that of Traveller John Reilly, arguably one of the most important figures in the field of ballads in recent history.
John was found by a collector in a poor state of health due to the conditions he was living under. Having recorded a number of extremely good and rare ballads from John, the collector decided to try and raise some money for him by getting him a few bookings at clubs - several of these jumped at the chance.
The leading Irish music organisation (at the time) Comhaltas Ceoltóiri Eireann was informed of John's situation and importance and asked to book him at their premises in Monkstown, Dublin - they refused, saying that John wasn't 'Sean Nós' (old style). John died of malnutrition in a derelict house in Boyle, Co. Roscommon not long after.
His saga didn't end there.
After John's death, the collector decided to devote the proceeds of any recordings of John used commercially to a school for Traveller children, but trustingly, sent some of these recordings to Peter Kennedy for his opinion. The recordings were immediately put into Kennedy's catalogue and remained there for sale in spite of requests to withdraw them. Neither the collector nor the Traveller children ever saw a penny from the sales.   
The sting in the tail of John Reilly's story was that after a well known revival singer recorded the best known of John's ballads, the extremely rare 'The Maid and the Palmer' (Well Below The Valley – Child 21), for which John was the only oral source, the 'copyright' of this made its way into the hands of the highly successful middle-of-the-road musician Phil Coulter.
On a lighter note – Harry Cox was once booked at The Singers Club (I wasn't there, but my wife was). When he started to sing he was obviously uncomfortable and wasn't singing well at all. After the second song he turned his back on the audience, spat his new false teeth into a handkerchief, put them in his pocket and proceeded to sing wonderfully for the rest of the night.
I have been perhaps unfair to list the problems raised by introducing traditional singers to the revival, many of them took to the clubs like ducks to water and became established performers there, and by and large, they were treated well. Only a very small percentage of them ever visited clubs anyway (I'll show you mine cap'n if you'll show me yours!). Most of the problems occurred because of thoughtlessness and insensitivity rather than intentional bad behaviour on the part of us folkies. I have only known one occasion in which elderly singers were treated badly deliberately. A reviewer who I had upset (by criticising his mentor) decided to get his revenge by savaging an album of field singers, mainly concentrating on our notes, but also directly insulting several of the singers, and ignoring all of the others (the songs were not discussed at all). In fairness to the reviewer, I don't believe he targeted the singers deliberately; they were merely 'collateral damage' as Condoleeza Rice so quaintly and delicately put it. As the reviewer's subject wasn't really traditional song (or music), he was unable to do any real damage (the album is a best seller in field recording terms and is now coming to the end of its third pressing), but the experience tends to leave a sour taste in the mouth and makes you think twice about making your fieldwork widely available where it can be got at by such people.
Other than this sordid episode, my memories of seeing traditional singers perform at clubs have nearly always been good ones and I have felt privileged to have 'been there'.   One of the most memorable nights we have ever spent was when we took a singer/storyteller and two musicians to Cecil Sharp House where they entertained a roomful of people, singing, telling storys, playing and reminiscing – all thanks to malcolm taylor's efforts.
I do think it unfair to suggest, as has been suggested, that we can judge the performance of traditional singers the way we would judge that of younger, more street (or club) -wise revival performers, and I believe without question that we have received far morefrom the tradition than we have given – we wouldn't have had anything to sing without the singers' generosity.
Jim Carroll
PS Having god-awful computer problems so can't respond to oreder Cap'n