I have been to concerts in Alexandra Palace a few times now and I every time I find myself staring at the building longer than the musician I am there to see. I found the design of the hall interesting and wondered what the inspiration was. I thought ancient Roman or Greek perhaps?
Alexandra Palace was built in the Victorian era and first opened in 1875.
Nothing But Thieves at Ally Pally - my photo
Concert Hall - Google images
Concert hall - my photo
From the last photo it is clear that the columns are in the style of the Corinthian Order.
Left: The origin of the Corinthian Order, illustrated in Claude Perrault's Vitruvius, 1684. Available at: https://en.wikipedia.org/wiki/Corinthian_order
Right: Corinthian Order. Available at: https://www.flickr.com/photos/designucdavis/130376828/