Do I detect a long, interesting and occasionally acrimonious thread opening up here; I do hope so.
Richard Bridge and Guest Russ are quite right; you are going to have to define what you mean by 'Tradition' if you are going to make a half-decent job of your project.
In my opinion, all you are going to get by asking your questions to members of this forum, is a picture of 'the revival', people who had nothing to do with a living tradition, but have come along from the outside and taken up the old songs and music. Unless Sheila Stewart, or one of the other of the miniscule number still with us avails themselves of a computer, you are not going to get a response from a traditional singer. I suggest you read through an earlier thread on this forum entitled 'What is Traditional Folk Song' and the related threads for background to this.
Unfortunately, there is very little information on the tradition, simply because the collectors never got round to asking the singers themselves. I believe that the nearest you have is 'Jeannie Robertson', James Porter's and Herschel Gower's study of the great Scots Traveller, but this falls far short of gathering enough information to give us a full picture of the tradition.
Here in Ireland the tradition lasted relatively late and the singers learned their songs mainly orally, from family members, from neighbours. Also from 'the ballads', the song sheets that were sold around the fairs and markets, mainly by Travellers, a practice which went on right into in 1950s, when records and the radio took over the role of entertaining the general population.
I suspect the answers you will get by asking forum members will be similar to those supplied so far by Captain Birdseye. We learned our songs mainly from books, records and from other revival singers. Those of us who have been involved for centuries started off with collections like A L Lloyd's and Vaughan Williams' 'The Penguin Book of English Folk Song', and MacColl's 'Singing Island' and Frank Purslow's selections from the Hammond and Gardiner collection 'Marrowbones', 'Foggy Dew'. 'Wanton Seed' and 'Constant Lovers'. In the early days we also had a wealth of recordings of real traditional singers, such as those made by the BBC, of people like Harry Cox and Sam Larner, and later the songs of Walter Pardon (arguably the three most important English singers in living memory). One of the changes that has taken place nowadays is that singers seem to me to now be learning their songs almost exclusively from other revival singers (along with the mannerisms, idiosyncrasies and accompaniments). Look through Mudcat and you'll find requests for 'Martin Carthy', or 'Kate Rusby', or 'Christie Moore' songs rather than 'Harry Cox' or 'Mary Anne Carolan' or 'Sheila Stewart' ones.
Thanks for starting this thread; I hope you get as much out of it as I think we might.
Jim Carroll