As I was saying, when I came back from my tour around Europe I went to work for Yale. Not on the faculty, at least not to teach.
I was going to work for Al Bromley, who was later to be [the elder] Pres. Bush's Science Advisor, to make his new laboratory work. I could talk to the engineers in the lab because they were the kinds of people I had been working with outside of school, I had a Ph.D., so I could talk to the scientists, I had been working for a supplier of scientific equipment (and occasionally selling it), so the vendors couldn't snow me, and my father was a tool&diemaker, so I could talk to the machinists in their own language. The lab went together better than anybody had any right to expect: not because the construction went without mistakes but because we could figure out ways to correct the mistakes.
After the initial round of crises I had time to look around, and I found that there was a bookstore in New Haven that had informal folkmusic gatherings. Later I found out that that was formerly a hangout for John Cohen of the New Lost City Ramblers, and the Ramblers may have gelled there. I started hanging out with a group of people, townies and graduate students, who were interested in "traditional" folk music.
I better say a few words about "traditional" "folkmusic" in the way I use those terms.
When Cecil Sharp took his flivver-&-muleback tour of Appalachia in 1913 through 1916 the people he heard singing and playing were "traditional" "folk" "musicians".
They were musicians because they made music.
They were "folk" because the music they made had not been influenced by official "classical" or "popular" music for some time, possibly generations.
"Classical" music is academic, and "popular" music is middle-or- low-brow entertainment; but both are created by professionals and performed by professionals. "Folk" musicians may be entertaining themselves or others, but the odds are that the entertainment doesn't stray much from their farm or neighborhood.
Classical music is based on aesthetic principles that are codified in universities, popular music is derived from watered-down classical arrangements of variations on traditional tunes, but the kind of folkmusic that Sharp collected was built on aestrhetic principles that had been traditional in the isolated backwoods settlements for generations. Some of the songs were recognizably in "modes", the medieval mustical structures that had been completely replaced by the notion of "keys" in classical and popular music. The important thing was that to the musicians that Sharp collected this wasn't "a kind of music" to be distinguished from other kinds of music, this was the way music was.
In the late 1920s, in order to market the new phonographs, recordings were made of rural musicians like the Carter Family and Jimmy Rodgers, who would sound familiar to the rural communities. It became possible for people like them to travel around and earn a living by performing their music in meeting-halls. Making these traditional folk performers into professionals blurred the lines between "folk" and "rural-style popular" music. This rural popular music broadened its listener base in World War II and became "County Music". That has spawned enough "crossover" singers with lush arrangement that furthur blurred the lines between country and popular; and that, in turn, stimulated a revival of the earlier rural styles as "roots" music.
The "folk revival" of the 1940s had been stimulated by singers like Burl Ives and political singers like Pete Seeger and Woodie Guthrie, who were interested in presenting a simple tune and clear words. Any folksong, from any source, American, Irish, Scottish, Jewish, even African, was ground down to a simple tune and clear english words. There was no sense that there was any aesthetic associated with a particular folksong other than American poular or parlor songs of the late 19th century.
Of course 20th century popular music has been powerfully influenced by the traditional music of african americans. From the synchopation of the Ragtime of the late 1800s to the harmonies of the blues, American popular music from the Civil War to Rock and Roll has tried to absorb every variation of African American music and make it acceptable to white audiences.
Folkmusicians of the 1960s revival were no different: to be popular they adapted the instrumentation of a Jazz band and the aesthetic of African-influenced popular music. They were so successful that in the music business "folk" now means music that is in the style of folk-influenced popular musicians of the revival of the late-60s-early-70s period or music that is a little more like country than "soft rock".