Prepping for a TV interview is not something most of us will ever have to worry about.  But for business leaders, politicians, celebs and other public figures it is part of the working day. 

They will prepare for those TV and radio interviews in different ways - quiet contemplation, reciting key messages or, in a new one to me, singing.

Sainsbury's chief executive is, as we learnt yesterday, a singer.  And his choice of song - We're in the Money from the musical 42nd Street - was perhaps rather unfortunate.  

The message all PRs give their clients and colleagues preparing for an interview is that the camera, microphone or recorder is likely to be always on. Watch what you say. 

In this case it wasn't a PR disaster.  He may be the butt of jokes, but no long term damage - in fact, Sainsbury's share price rose by 17%. 

But it could have been worse - just imagine if he was caught singing Rick Astley's Never Going to Give You Up or or Tears For Fears Everyone Wants To Rule The World!