There are, at least, two groups by this name. Ballyhoo (without the exclamation mark!) is a South African group who had a huge hit in 1980 in their homeland with their single 'Man On The Moon'. This South African group is still going strong. The other group with the same name (but with the exclamation mark!) is from Maryland, USA, a modern rock/reggae party band, active since 2006.
These are photos from concerts where Ballyhoo! played, so they may be of other bands that played the concert as well.
Pot Of Gold Music Festival Mar 18, 2018 Chandler, Arizona, United States Uploaded by Sophie♡