Can't control quodlibet 'Unable to init server'

[Chris Green]

When I try to control a quodlibet instance it doesn't work and I see
the following:-

chris@lounge$ quodlibet --play-file 'Bryan Bowers - The View from Home'
Unable to init server: Could not connect: Connection refused
chris@lounge$

Am I missing something obvious somewhere, i.e. how do I run quodlibet
as a 'server'?

--
Chris Green