There is a book about the opera in London entitled Fashionable Acts: Opera and Elite Culture in London 1780-1880 by Jennifer Hall-Witt that I would recommend.
Book Blurb: In a brilliant reassessment of British aristocratic culture Hall-Witt demonstrates how the transformation of audience behavior at London’s Italian opera–from the sociable, interactive spectatorship of the 1780s to the quiet, polite listening of the 1870s–served as a sensitive barometer of the aristocracy’s changing authority. She explores how the opera participated in the patronage culture and urban sociability of the British elite prior to the Reform Act of 1832 when the opera served as the central meeting place for the ruling class during the parliamentary session. The vertical tiers of boxes at the opera highlighted not only the gendered nature of elite political culture, but also those features of aristocratic society most vulnerable to critique by political and moral reformers.
Hall-Witt shows how the elite adjusted its behavior in public venues, like the opera, partly in response to such criticisms. Offering a revised chronology for the decline of the British aristocracy based on such cultural compromises, Hall-Witt reveals how the very adaptations that helped the landed elite to survive as the ruling class into the Victorian period also undermined its ability to maintain its power in the long run.
One function of the opera was for the audience to see and be seen. It took time for the audience to come and listen to the music and see the drama. Most of the book is concerned with the time to 1840 and less afterwards.
“The Covent Garden Theatre, the original theatre on the site, was opened (1732) by John Rich and served for plays, pantomimes, and opera. During the 1730s, when George Frideric Handel was associated with the theatre, opera was emphasized, but later the focus shifted to plays. Managers in the late 18th and early 19th centuries included the noted actors George Colman the Elder, John Philip Kemble, and Charles Kemble. The structure burned in 1808 and was rebuilt in 1809. In 1847 it became the Royal Italian Opera House under the noted conductor Michael Costa and, later, Frederick Gye. The building burned in 1856, and a new building was opened in 1858. The Royal Italian Opera failed in 1884 and was replaced in 1888 by what came to be called the Royal Opera Company under Augustus Harris and, later, Maurice Grau; the repertoire was largely Italian opera.” [Britannica]
For more information on the type of people who attended the theatre, I would recommend Rachel Knowles’s piece found HERE.
“According to Feltham’s The Picture of London for 1807 the numbers of people that could be accommodated in the theatre and the prices for each type of seat were:
“The doors opened at 5.30pm and the performance started at 6.30pm. People could be admitted for half price at the end of the third act of the play which, according to the The Picture of London (1809), was ‘generally a little after eight o’clock.’3 The Picture of London (1813) went into a little more detail, specifying that half-price began at the end of the third act of a five-act play but at the end of the second of a three-act play.”
In the early 19th century, box subscribers received a reduced price for the season in exchange for payment up front. They were supposed to let the management know when the box was not being used so the tickets could be sold again by the theater. Since the members of the ton were notoriously lax about this, at times theaters actually hired people to question servants and find out what people were doing. I am guessing that if the box holder provided use of the box to a party that did not include anyone on the subscriber list (the box holder provided the theater with a list and families quite often shared a box) they had to inform management.
I am fairly certain that by 1864 things had changed dramatically. There were a greater numbers of rich people in London by then and I assume the opera house had no problem selling out on a regular basis without the subscription method of financing the season. You could check the Annals of Covent Garden (available on Google Books) and see if it says anything about when things changed in that manner. Most of my information comes from a compilation of newspaper clippings about the King’s Theatre in the British Library, plus various other theatrical histories.
If one is planning to include an opera scene in a book, etc., I would suggest he/she conducted research on individual theaters. There were a limited number of theaters and not all of them preformed operas (or even dramas). They also had set seasons when they were open and performing, which might affect a particular story line.
Some possible sources include:
Plays About the Theatre in England, 1737-1800 or, The Self-conscious Stage from Foote to Sheridan by Dane Farnsworth Smith and M. L. Lawhon
The Cambridge Companion to British Theatre 1730-1830, Edited by Jane Moody and Daniel O’Quinn
A good basic bit of info is here:
http://main.thebeaumonde.com/archives/5171 Most who liked the theater or opera would keep a box subscription. This would be kept up in several of the theaters (for the rich, cost wasn’t a problem). It would be unlikely that anyone would let their box to another–but they might offer its use to friends and/or relatives if it was not in use. Otherwise, it would be left vacant for that performance.
For a reference book on opera – http://www.pickeringchatto.com/titles/1092-9781848931657-london-opera-observed-1711-1844