This was the Esperanto Association of Britain's site from 2005 to 2018. You will find its current site at esperanto.org.uk.
The event is also featured as the "cover story" with this announcement on the shoplechworth.com website:
Guinness World Record Concert
Leys Square event Saturday 5th May 2007.A French entertainer will attempt a new world record in Leys Square, Letchworth Garden City on Saturday May 5 from 12:30 pm, when he will sing 25 songs in 25 languages
Jean-Marc Leclercq, whose stage name is Jomo, was listed in the French edition of the Guinness Book of Records in 2000, as having sung 22 songs in 22 languages. "I am now going for a new world record, with 25 songs in 25 languages", he said.
Tickets to reserve a seat for the record attempt concert are available at £1 each from Letchworth Arts Centre (01462 670788). However, all are welcome to this amazing open-air event, which is being organised by the British Esperanto Congress, in association with Letchworth Town Centre Partnership and Garden Square Shopping Centre.
Congress website: www.britakongreso.org.