The Llangollen International Eisteddfod is facing a “particularly difficult” period, organisers have warned.
Its new musical director Dr Edward-Rhys Harry said the event, which runs until Sunday, needed to be more “modern and relevant”.
And the eisteddfod’s chair Dr Rhys Davies acknowledged ticket sales had been “disappointingly low” compared with 2018.
The annual week-long festival has been running for more than 70 years.
Last year it attracted 40,000 visitors to the Denbighshire town.
In 1955 a 19-year-old Luciano Pavarotti appeared at the event with a choir from his home town of Modena, Italy, and won first prize.
He said the experience inspired him to launch his singing career.
But the event’s latest financial report showed an increasing deficit in 2018 – from £5,860 in 2017 to £21,127 in 2018 – after “lower than expected sales” for some evening events.
The report states: “The trustees are very aware of the stringent financial restraints which will be necessary for the next few years and intend to monitor closely costs and sources of income to improve the financial status of the eisteddfod and secure its future sustainability.”
The festival has just received £75,000 from the Welsh Government’s major events unit to help with marketing over the next three years.
“Every year becomes a struggle I’m afraid,” Dr Davies said.
“[This year is] going to be very important because we need to engage with other supporters to make sure we can continue.
“It’s going to be a difficult [year] and I see the next few years are going to be particularly difficult.”
Dr Harry said he had plans for big changes to the event in future.
He warned some could find the changes “radical”.
“I certainly feel that the eisteddfod needs to come more modern and relevant to society in what it offers,” he said.
He added: “I don’t want to throw away traditional stuff, but I also feel that having had a look around at other festivals that are maybe not too far away in Liverpool and Manchester and places like that, there seems to be a more edgy quality to some of the offerings.
“And I think we can find a way of balancing the things that we do here traditionally alongside some more edgy acts if you like, or some more edgy events.
“There is no doubt that some people may feel that it is a bit radical.
“But it is important that the eisteddfod develops and that it survives.”