So there was "folk", which meant a set repertoire of songs, mostly involving milkmaids. Then there were "folk songs", which meant songs that ordinary people recognised as their own, whether it be Greensleeves or Auld Lang Syne or You Need Hands. Then there were "folk songs" meaning songs that expressed the radical strivings and yearnings of ordinary people, usually involving union representation. And then there were "folk singers", usually meaning beardless youths singing their diaries.

But that's not all. Then there was progressive rock, which made folk look ridiculous by opening up both musical and lyrical possibilities - strange chords, strange time signatures, strange metaphors, why would you go back to the milkmaids (or the trade unionists, or the singing diaries)? There should have been some common ground with milkmaid-folk - which is as weird as you like in places - but the opportunity was rarely taken. And then there was punk, which made folk look ridiculous all over again by privileging authenticity, spontaneity and anger: there should have been some common ground with both radical-folk and diary-folk, except that punk offered to do everything both of them were doing and do it better (and angrier).

And that's just the story up to about 1979. Folk has been left behind over and over again by the March of Trend - I've often wondered whether what did for Peter Bellamy's career wasn't the success of the Transports but the unpredictable coincidence of that succss coming in the year of punk. And traditional folk has been left behind over and over again by folkies who think their interpretation of folk is better suited to catch the wave. And yet we're still here, and the old songs still sound amazing.