Singer Christy Moore revealed he took the decision to cancel two sell out shows with a "heavy heart" after being struck down with a sore throat.
The Co Kildare-born singer said he felt "dreadful" as he was aware many of his fans were already travelling to the Bord Gais Energy Theatre for last night's performance.
"It is many years since I have had to cancel a performance. It is a low point in my working life," said the popular singer, after two new dates were rescheduled for early February.
The singing star revealed that he was aware people had "travelled long distances by air, road and rail" and that they might not have learned of the cancellation as they were already making their way towards the venue.
The singer visited his doctor after waking with a sore throat which left his voice weak and croaky on Monday. He was forced to call off the concerts after being unable to sing yesterday afternoon.
"I tried singing at public performance level and nothing came out at all," Mr Moore said.
All tickets for the January 15 show will be valid for the rescheduled show on February 1 next, and all tickets for tonight's January 16 performance will be valid for February 2 next. Christy Moore fans Denis and Aideen McCarthy, who had tickets to tonight's gig took the disappointment in stride: "C'est la vie! We hope he gets better soon and look forward to seeing him in concert in February."
Promoters and the venue attempted to get the word out to fans via the internet and the radio, while in the hours before the doors opened alerts were also sent to ticket holders' mobiles.