Beautifully shiny colours, sitting making a lovely chattering sound.
No interactions present.
Difficult to tell from your picture, I'm afraid, though I believe you! For some reason the large version of your picture does not open properly. If you would like to edit your observation you can try adding the file again (I think the existing one is corrupted).
University of Edinburgh and Biodiversity Observatory (OU)
But from your excellent description you have clearly identified this bird correctly. I rate starling song as the second best in the UK, after blackbird.
Lat/Lng: 52.0, -1.5
OS grid ref: SP3937