Published Saturday, 11 February 2012
The Mulholland Grand organ is considered one of the most significant of its kind and is one of Belfast's prized possessions.
But it was unlocked on Saturday giving everyone from the keenest enthusiasts to novice players a once-in-a-lifetime chance to get in tune.
"It was brilliant," one boy told UTV. "You never get the chance to play on an organ like this.
"This is usually locked up and not many people get to try it so it was good."
Another girl said: "I've heard a lot about the organ and how grand it is so it's really amazing to be coming here and getting to perform."
The city's pipe organ is itself around 150 years of age.
It was installed in December 1862 - just six months after the hall was opened.
Organisers of the open day hope it gave people the chance to learn a little bit more about the dramatic instrument.
City organist Colm Carey said: "What we're trying to do is actually have it available for anyone who wants to come and have a go.
"They may have been at many pop concerts, festivals or whatever here at the hall and seen this magnificent instrument at the back.
"Now they've got the chance to explore it and see how it sounds."
© UTV News