The Preview Club, at the Spread Eagle in Southend on Sea, pretty much defies description. It is a genuinely open mic gig — and David Anton, whose baby it is, has run it, week in and week out, since 1984, offering a stage to just about any kind of music you can think of, although even he might be just a little surprised if the Hallé Orchestra turned up in full force. He'd find a way to do it, though!