Eurovision stars Brotherhood of Man were the surprise celebrities for the grand finale of the TV filming in Shepton Mallet town centre.

Their appearance was a closely guarded secret as the two months filming for the new prime-time BBC series focusing on changes in British shopping habits over the last 150 years reached its closing climax.

The group wowed the appreciative crowds and performed many old favourites including Save All Your Kisses For Me, Angelo and United We Stand, Divided We Fall.

Hundreds of old and new fans packed out Market Place to hear the group, who in their hey-day held the Number 1 spot in 30 different countries around the world.

The filming finished with a huge street party – forced by heavy downpours from the Market Place into the shelter of the Academy Theatre – where townsfolk said a fond farewell and thank you to the film crew and the shopkeepers and their families who have made their mark on the town.

Suggestion boxes are now in the library and the tourist information centre for people to say what they hope will come out of the town being chosen for the series due to be screened Sunday nights in November and how Shepton can best capitalise on the fame they hope it will bring.

A steering group has been formed to ensure Shepton does not lose out on the opportunity to use the programme to encourage visitors and investment.

Town council chairman Jeannette Marsh, who with husband Terry was among the core shoppers throughout the series tracing changes in shopping habits from the 1850s to the 1970s, said: "We would not have missed it for the world. It has been an exceptional experience and I am sure it will open new doors for Shepton Mallet. We look forward to welcoming many people who will want to come to see Shepton after it has been made famous."

TV superstar Greg Wallace, co-presenter of Masterchef, who will present the new history programme said: "I never knew anything about Shepton Mallet before this – I thought it was just somewhere between Bristol and Bath. But coming here and getting to know it so well has been an absolutely amazing experience. I don't think any programme has tackled anything like this before – it is going to be utterly incredible. It has been the most unique experience to be involved in something like this and I have made so many friends while being here."

Mr Wallace has had to juggle filming between the history show and the latest series of Masterchef and also squeezing in a family holiday in Florida. He flew back especially from Florida for the final day's filming and end-of-series street party."I would not have missed it for the world – I have met some incredible, amazing, friendly people here. We started off with a polite nod and a hello – and now we are all firm friends."

Mr Wallace says the programme will deliver a strong message to shoppers. "I am not anti-supermarket – I am a realist and I realise supermarkets are here to stay. But I just really hope this programme breathes life back into Shepton Mallet town centre as it is the most amazing place," he said.

"I don't think anyone – town planners, councils, developers, people – ever realised when we embarked down the road to out-of-town shopping centres and giant superstores what it could mean and how it could affect our town centres and high streets.

"Anyone seeing this series will want to bring back our dear old High Streets – but there are now no High Streets to bring back.

"We are all guilty, you and me, our parents and our grandparents, local government – everyone who made the decisions in those early days that out-of-town shopping was the way to go, and everyone who turned away from High Street shopping and made that choice to shop out of town.

"I don't think many places actually realise what they have done – but here I am actually witnessing it here in Shepton Mallet first hand.

"If people of all types shop together, chat together and start caring about each other again it can only make it better for the whole community – and make that community more prosperous, safer and happier.