The Warfield Churches choir had planned to make use of the bandstand to plug in their instruments and set up speakers, but arrived in the morning to find the outdoor High Street venue had no power.
But the 23-strong group were undeterred and soldiered on, serenading passers-by with no microphone or accompaniment.
Organiser and choir member Jenny Bentley said the afternoon went well in spite of the hiccup and added: "We used our initiative and people were smiling and waving as they want past us.
"The idea was just to bring hope to our community."
The choir sang traditional carols for three hours and also performed the same set at Beech House care home, in London Road, Binfield, on Sunday.
St Michael the Archangel Church, in Church Lane, Warfield, will hold Midnight Mass with the choir from 11.30pm on Christmas Eve. "That really is our big event," said Mrs Bentley. "This is our fifth year as a choir and we really are growing, it's very popular and encompasses all ages - teenagers up to people in their 70s."