The climatic scene at the "Boston Music Hall" was actually filmed at the Troy Savings Bank Music Hall in Troy, New York, finished in 1875. The Boston Music Hall was pulled down in the 1950s. But the film required a civic hall with a pipe organ in it for plot reasons. While we see the 1882 Odell organ in the Troy hall, the organ itself didn't work very well in 1983, so the music was actually recorded on the organ at Mechanics Hall, Worcester, Massachusetts.
During filming, actress Madeleine Potter noticed that one of her costumes had the name "Nastassja Kinski" sewn into it. As it turned out, the dress had originally been made to be used in the movie Tess (1979).
Vanessa Redgrave replaced Glenn Close in the lead female role of Olive Chancellor. Close had agreed to play Olive but dropped out to film The Natural (1984). Close once said of this: "Finally, I got to play opposite every woman's fantasy, Robert Redford, and I never got to touch him!". Olive Chancellor was played in the end by Vanessa Redgrave who got Oscar nominated for Best Actress. There was a convincing belief prior to the ceremony that Redgrave would never win due to her controversial anti-Zionist spiel from her Oscar acceptance speech in 1977. According to Ivory, "I wanted as much as possible to have a completely American cast, but we were never able to work that out. We couldn't get a suitable American address to play that kind of part, so we sent Vanessa Redgrace the script, and she's marvelous. So I accepted her, English though she is with an English accent. In the 30s and 40s they used to hire English actors all the time for American films to play upperclass parts, remember? So I suppose I accept her on that basis.
The film was made and released about ninety-nine years after its source novel of the same name by Henry James had been first published as a serial in 'The Century Magazine' in 1885-86 and then in novel form in 1886.
According to the official website of Merchant Ivory Productions, source author "Henry James first conceived the [film's source "The Bostonians"] novel through his fascination with the cause of suffrage".
According to Margarita Landazuri at the Turner Classic Movies website, "...the origin of the term 'Boston Marriage', which in the late 19th century came to describe a marriage-like relationship between two women who live independently together without a man's support, is attributed to [Henry] James and his novel. [Henry] James is believed to have drawn the inspiration for Olive [Chancellor] and her fellow suffragettes from his sister Alice, who lived with another woman in a Boston marriage".
Christopher Reeve said of this film in his autobiography "Still Me" (1998): "[Producer] Ismail [Merchant] could only afford to pay me [US] $100,000, less than a tenth of my established price at the time. I insisted that the money was not an issue, that this was the kind of work I ought to be doing, but my agent told me, 'If you do that picture with those wandering minstrels, it will be one foot in the grave of your career'. ... I cheerfully ignored their advice".