The 'Voice' coach attended the Irish indie rock group's show at London's Borderline with bandmate Glen Power and decided to join in for a stunning rendition of their song 'Heroes or Ghosts'.
Speaking afterwards he said: ''Best band in London, I just gatecrashed the gig.''
Although The Coronas have made a name for themselves in Ireland releasing three albums, 'Heroes or Ghosts', 'Tony Was an Ex-Con' and 'Closer to You' to critical acclaim, they admit they will have to work hard to recreate the success in the UK.
Frontman Danny O'Reilly said: ''It's been so long since we played London, we didn't think anyone would show up. This is our beginning, we've been doing well in Ireland but this is where it all begins we hope.''
The group - which also includes Dave McPhillips on lead guitar, bassist Graham Knox and Conor Egan on drums - impressed the crowd at the sold out venue with a selection of songs from their back catalogue including 'Someone Else's Hands', 'Tony Was An Ex Con', 'Addicted To Progress' and new single 'Mark My Words'.
They tweeted after the gig: ''Amazing tonight,joined on stage by @thescript_danny with glen from@thescript @thewhitmore @eoghanmcdermo there too#deadlycelebmatesnamedrop (sic).''
The Coronas are currently on a UK tour, for more information go to thecoronas.net