If the Bayreuth Festival is for the elite or at least the very dedicated then the BBC Proms in London is the summer festival for the literal masses. The Royal Albert Hall seats 5544 and the concerts occur daily for 58 days. There are multiple concerts per day plus the last night of the Proms can be seen via satellite in multiple venues across the United Kingdom.
...2016 season launch
The festival starts on July 14 and concludes on September 10. Ticket prices start at £7.50. After the whole Brexit thing and the drop in the value of the pound, the tickets are even more affordable. If you pay with euros they deport you.
The amount of music performed at the Proms is staggering. Each concert is unique; there are no repeats.
I went to the calendar and randomly clicked on the week of August 15. There are 26 concerts from Monday to Sunday.
The list of composers is hard to believe: William Byrd, J. S. Bach, Arvo Pärt, Beethoven, Mozart, Tchaikovsky, Berlioz, Liszt, Wagner, Prokofiev, Thomas Adès, William Walton, George Finzi, Leonard Bernstein, Cole Porter, Leos Janacek, György Ligeti, Haydn, Mendelssohn, and others. Keep in mind those are the composers being performed for that week.
The Proms calls itself, “The world’s greatest classical music festival.” There is no argument — unless we want to get elitist and go to Bayreuth.