At Old Songs a few years back, Roy Bookbinder was performing in an informal group. One "fan" kept singing and playing along LOUDLY. Bookbinder changed tempo so slightly as not to affect his performance but threw off his "accompaniest" completely. Wonderful to see.

He was not as successful with the clod in his face with a video camera. The photographer was told not to, was accused of stealing his techniques, was outright insulted but kept smilingly filming away.