Derek was responsible for a line which I can still hear him saying, twenty-odd years later.

At the Wath-on-Dearne festival, early 1980s, he was performing in the main concert hall. As is often the case, a few kids were getting restless, with one in particular whining and bawling every few minutes. Derek stopped mid-song and just said "Shut that kid up before I murder it". Much laughter, huge round of applause, and end of problem.