At charity music festival Zacfest - being held at the Telford Town Park on Sunday - a crowd will be trying to become the most people dancing along at once to The Baby Shark song, which has been an annoyingly catchy favourite among children everywhere.
The record attempt will be done in the name of Zac, who is a big fan of the song.
Zac has an extremely rare form of childhood leukaemia called Near Haploid, and needs to travel for specialist treatment unavailable on the NHS.
People across the county have come together to raise half of the £500,000 needed to get him to America, and Zacfest is the latest effort to reach the target.
As well as the record attempt, the day will include performances from Escala from Britain's Got Talent, The Endings, Ska Burst, Savannah and Black Bear Kiss.
Zac's mum, Hannah Oliver-Willets, said it was incredible how quickly the event had been put together.
How you can help:
Anyone who wants to support the fundraising campaign should visit justgiving.com/crowdfunding/zac-oliver
Anyone donating is asked to make sure they post a picture of themselves wearing red on September 28 on Facebook or Twitter with the hastag #wearredforzac
People can also join Zac's Facebook support page which is called 'Zachariah's's fight against Acute Lymphoblastic Leukaemia'.
People can also donate using their mobile phone by texting ZACH75 £1 to 70070.
"It's gone from the idea of having a concert to suddenly getting some really good headliners and lots of people wanting to sponsor us to get the festival off the ground," she said.
"Rob Wallace has pulled this off. He's organised it, and everybody has given him a hand along the way. He's put so much energy into it, I don't know how he's done it in such a small amount of time.
"I really do believe with the response we've had it's going to be epic. If we can make sure we get this baby shark Guinness World Record pulled off, which we can, then that's going to be amazing."
Hannah said it was nice to have something fun for the family to look forward to.
"I think it is a fantastic way for the community to come together in one place and just have fun. Everybody is campaigning so hard to raise the funds that we need for Zac, and this is a way that everybody can come together, let their hair down and have a party.
"In among all the stress and sadness, the hard work, actually we can all get together and have fun."
Zacfest will take place at Telford Town Park from 10am until 10pm on Sunday.
Tickets cost £5 for adults, £2 for children and £12 for a family of four and will be available to buy on entry.