In Madison in the 60's at one time or the other I knew or met:

Carolyn Hester

Danny Kalb and his unknown younger brother Johnnie (both great guitar players)

Paul Prestipino, who might be the same person as Greg Prestipino (?), an incredible mandolin and banjo player

Phil Buss, guitar player and maker(last seen in Santa Fe in the 90's)

Tracy Nelson, blues belter of "Down So Low" and Mother Earth fame

Mel Storch, banjo

Of course lots of famous performers played Madison in the early 60's starting with Joan Baez and later Dylan himself, but since Chicago was only 3 hours away we used to go down to the University of Chicago Folk Festival where there was a lot more traditional folk music to enjoy. People like Flatt and Scruggs, the Carter Family, Doc Watson, Big Joe Williams, Gary Davis all played there in the years I went. In addition to the great concerts cause we were on he scene we always got to go to the afterhours party in somebody's flat where you got to see and hear some of these same luminaries in the intimate setting of a livingroom--until the police came and rousted us all out onto the frozen streets because of a noise complaint.

I particularly remember Big Joe Williams and Rev. Gary Davis performing at one of these parties, and at that or in another year, Paul Butterfield, as yet unknown, was in the hallway practicing licks from "You Gotta Help Me Baby, I Can't Do It By Myself" while simultaneously putting the make on a girl with long blonde hair, the lyric ostensibly being his come-on line. I'll never forget that. A couple of years later the Butterfield Blues Band was packing them in at Big Johns in Oldtown and we'd go down on weekends to catch them cause it was a really hot scene. One time while we were dancing I realized that the woman who I was having such a blast dancing with was none other than Odetta.

Barry Goldberg was someone I also hung with once or twice in chicago.

As to other not-so-well-knowns I can think of:

Diane Davidson (maybe more country music), saw her play in San Francisco a couple of times.

Jesse Winchester

Kate and Anna McGarrigle

Ewan MacColl and A.L.Lloyd who had a couple of albums of Sea Shanties