My first memory about "Proms" was that when I stayed London for summer school about 1 month, some of students were talking about Proms. And recently I happend to watch BBC HP and found that I could hear all program of Proms from here. I recollected my London's memory after 16 years.
What I felt at UK,also traveling around EU, was that music is a part of their life so I can hear very beautiful classic music played by young college students with violines, etc. I was deeply moved.
As seen this Proms's program, there are of course standard music lineup but also latest ones like world premium of "The Little Mermaid", so the width of variation makes me surprised.