"No folksingers need apply!"

That's not exactly what happened. Security was very tight in Washington Square Park on the eve of 9/11, and for good reason. Many of the speakers denounced not only the coming war in Iraq, but the current war against Al Qaeda and similar terrorist organizations. Also many of the speakers were from Arab-American and/or Muslim organizations. It was not a vigil in the usual meaning of the word, but more of an anti-war rally with candles.

Anyway, Steve (much as I like him) is a little confused. Pat Humphries performed from the stage, and she is certainly a folksinger. The security marshals at the gate searched her guitar case before allowing her in.

The issue wasn't whether you were a folksinger or not, but whether you performed with amplification. Those who used the amplification were allowed past the security gate. Those who performed without amplification were quite properly directed to the fountain area where they would perform after the power was turned off. This included a 25 piece classical ensemble from Brooklyn as well as a dozen or so folk musicians.