I'd enthusiastically add my vote to Promoters of Folk Music - many, many, many, and so few of them known outside their own bailiwick. It's not just concerts, and clubs, but those who teach, host/anchor singing sessions, tune sessions, folk dances/ceilis, feature the music on TV or Radio - and now websites (Thanks, Max!) - The whole support infrastructure that makes it possible for us to know of, hear, or meet the people to whom folk music is an intrinsic part of themselves.

Who comes to mind as the carriers of the tradition with whole life involvement:

All the Seegers : Ruth Crawford, Mike, Peggy, Tony - Pete gets the most note, but the others are significant
Martin Carthy - every decent guitar player or ballad singer I've met revers the man.
Sandy & Caroline Paton - singers, sources, promoters, support and encouragment
Peter Barnes - made English Country Dance music easily available to all of us who will never play as beautifully as he
Jean Ritchie - there are chapters on how important she's been right here on Mudcat
Frank Harte - find an Irish trad singer who DIDN'T get at least one song from him, and I'll eat my hat.
Lou Killen - in so many ways, in so many situations, for so many years
John Roberts & Tony Barrand - who pretty much define a genre of their own.
The Armstrong Family of Chicago - Gerry, George and their daughters.
Art Thieme, of course.

My list doesn't include large swathes of tradition that aren't as close to my heart, but I know they're out there in cajun, old time, swing, western, early county, world music outside the US... we've a debt far and wide. I hope they all get the thanks they deserve while they live.

Joanne In Cleveland