Oh, puhleese! I've definitely seen Pavarotti use a mic. Do you know what? He still projects - he just knows to stand well back from the mic stand. Inaudibility's far more of a barrier between singer and audience.

Does amplification matter? What would most "source" singers have done if it was available to them? We don't live in hermetically sealed communities, nor did we ever, even when the pace of change was slower.

As for numbers of folk clubs in 1970, this is an interesting one - there seem to be lots of ballpark figures thrown around for the early 1960s but as the numbers increased and clubs opened and closed with rapid turnover I suppose it was harder to keep track of the figures. It would be fascinating to hear if anyone's attempted the actual statistics.