This clip has a charming spontaneity and is surprisingly well recorded. At first it seems the piano playing may have been dubbed in post-production but the microphone picks up Winifred singing and the workers applauding at the end so it was recorded live. Most probably the microphone was placed directly into the sound board of Winifred's beloved upright honky-tonk piano, which would also explain why clip is silent at the start.
This short clip makes the most of a single camera shoot with a number of pans, cutaways and close-ups and is very effective in capturing Winifred's performance and the appreciation of the construction workers around her.
Construction on the Opera House commenced in 1959. It was envisaged that it would take four years to build but it wasn't until 1973 that it was finally completed.