It was ear-splitting applause, as the audience rose up out of their seats cheering, clapping and whistling.
Even Grainne Holland looked somewhat taken aback by the reaction, and when prompted to come back on stage for an encore she admitted she hadn't prepared anything.
But then the daughter of murdered greengrocer Harry Holland gave proceeded to give a flawless encore performance that met with a standing ovation.
Singing to a packed to capacity Culturlann in west Belfast as part of the Feile an Phobail festival last night - in which she launched her first album, Teanga na nGael, dedicated to her late father - the 31-year-old overcame her nerves and emotion by the end of the first song to give a rousing performance.
Extra seats had to be brought in to the 150-seat theatre such was the crowd that showed up.
Family and friends were joined by visitors from Dublin and Chicago as they watched Grainne wow the audience.
While she admitted at the beginning in a short speech that she would "end up crying" if she kept talking, the set was more upbeat and celebratory than some may have expected.
At times it resembled more a knees-up in a bar as the traditional Irish music got everybody's toes tapping and hands clapping.
But there were occasions - such as when she sang her only song in English, The Blue Hills of Antrim - that a few people could be seen wiping tears from their eyes.
Grainne sang a number of songs from her new album, singing in Irish, Scots and Manx Gaelic, ranging from the sad and haunting to upbeat and lively.
When she first took to the stage, following the instrumental song from her album written for her father, Harry Holland's Tune, the crowd erupted into cheers.
"I feel totally overwhelmed by the amount of support and people who have come out to see me tonight," she said.
She said she knew her father was in the audience watching her.
Dr Sean Mac Corraidh, a former teacher of Grainne who she credited during her set as sparking her love of gaelic music, said her performance was "absolutely brilliant".
Kathy Murphy, who watched the performance, said it was "really beautiful", and Donall Mac Murchaidh, a friend of Grainne's, said it was "absolutely fantastic".
Speaking to the Belfast Telegraph earlier in the day during rehearsals for the show, Grainne spoke of how her father had influenced her love for music.
"My daddy loved music and he always encouraged me to sing," she said. "He spoke Irish but he wasn't fluent. However, he loved the fact that I could sing in Irish and he used to ask about the stories behind the songs."
Grainne had been part of the Belfast pub-singing scene in her early 20s but it was always her dream to produce a traditional Irish album. However, it was only after losing her dad so tragically that she found the strength and confidence to fulfil her ambition.
"I know part of the reason for my confidence now is that I know my daddy is watching over us and I want him to be proud," she said.
Grainne has been working on her album, which is a collection of her favourite Irish songs, for the past six months after receiving an award from the Arts Council.
Although it is still early days she hopes critics will be kind.
"Critics will be critical - they are not going to dress it up just to make you feel better - but thankfully the reviews so far have been positive.
"I would like to be able to think about becoming a full-time musician. That would be wonderful."
Popular west Belfast shopkeeper Harry Holland (right) was stabbed to death with a screwdriver as he tried to stop car thieves stealing his delivery van from outside his home on Norfolk Drive. Neighbours tried to help the popular father of four, but he died shortly after being admitted to hospital. The attack happened in September 2007. The Holland family have led calls for tougher sentences for the three teenagers involved in Harry's murder.