Hi Roughyead (Not Bob is it?)
I wasn't present at this 'singaround' but this type of singaround has been running now for at least 30 years at festivals, whereby booked guests run the singaround and are expected to put in a performance for an unspecified spot or spots and if any well-known guests turn up they are also given a 'spot'. As I say I wasn't there so I can only make general comments. I'm not trying to justify what happened, only trying to explain how it may have come about. If I'm running a singaround I make sure everybody gets a fair crack, and before the 'star turn' does a spot I would make sure everyone in the room had had the chance to sing one song.

It's unlikely the organisers will be on Mudcat so I suggest you let them know what happened and ask them to specify the type of event more clearly in the programme. It should perhaps be billed as 'A Couple of hours with booked guest, and some floor spots' rather than as a 'singaround'.