I saw them in Rec Hall in 1968, just after the Bookends album came out (opening act -- PSU's own Woolly Thumpers), and again at the 1981 concert in Central Park.
Earlier, I was living in York and had a bunch of regular radio stations I used to listen to. I had on WKBW in Buffalo during the daytime, so it wasn't coming in very well. The announcer said, "the next song is by a group with the unfortunate name of Simon & Garfunkel." He then played the acoustic version of "Sounds of Silence."
I wanted to hear it with clearer quality, so I called up the local rock & roll station (WSBA) and said, "Do you have The Sounds of Silence by Simon & Garfunkel?" The guy must have thought it was a prank, and he hung up on me.