just shout "Rooftops"
I remember shouting the name of a long past pop tune artist which was being played over the PA. I talked several trade stand holders and none of us could recall the artist.
When the name finally came to me, I shouted it very loudly so all the trades people would know the answer (the tune was playing again). The whole hall went astounding quiet for several seconds and my wife tried to hide under a table!
Got the message across and, us and the stand holders (as my wife is well known in that particular pass-time/hobby circle), all had a laugh as we progressed arond the hall throughout the rest of the afternoon.
Just for the record, and for the unlikely chance that anyone on here was there that day, the tune was 'Venus in Blue Jeans' and the singer was Mark Wynter.
Shows my age and my mischievous streak.
Regards, RAB