Betty Freeman: Arts patron and champion of modern classical music

Betty Freeman was a significant photographer, whose portraits of artists, composers and musicians have been exhibited internationally, including a 1996 show, "Music People & Others: 99 photographs from the contemporary music world" at the Royal Festival Hall in London. But she will be remembered by history as a Maecenas, the single most important sponsor of contemporary serious music of the latter half of the 20th century.

Between 1961, when she made her first grant, and 2003 (when she did a tally herself) she had made 431 grants and commissions to 81 composers. And because she really worked at her philanthropy, and had a wonderful ear, many of these were made early in the recipient's career. John Adams's opera Nixon in China (1985-87) was dedicated to her, as were two works by Steve Reich, John Cage's Freeman Etudes, and Lou Harrison's Serenade for Betty Freeman and Franco Assetto (1978) – Assetto was her second husband.

Her beneficiaries included Philip Glass, Thomas Adès, Harrison Birtwistle, Thea Musgrave, Conlon Nancarrow, Ned Rorem, Kaija Saariaho, Virgil Thomson, Witold Lutoslawski, Matthias Pintscher, George Benjamin, Morton Feldman, Esa-Pekka Salonen, the director-producers Peter Sellars and Robert Wilson, and the dance troupes of Merce Cunningham and Bill T. Jones. She was also the subject of her good friend David Hockney's great 1966 painting Beverly Hills Housewife, which hung in the dining-room of her Los Angeles house.

Born Betty Wishnick in Chicago in 1921, she was brought up with her two brothers in Brooklyn and the affluent Westchester County suburb of New Rochelle. Her father's fortune was made as a chemical engineer, and her mother taught maths. She took her undergraduate degree in 1942 in music and English from Wellesley College. She married Stanley Freeman soon after graduation, and they had four children together. Following their divorce she married the Italian sculptor and painter Franco Assetto, with whom she lived half the year in Turin, and half in Beverly Hills.

In an interview she gave in the early 1990s, she explained her gift-giving as a family tradition: "My father was a philanthropist who gave to hospitals, to Israel, and to education. He was always aware of the needy, the poor and the sick. So I learned this lesson early that it is better to give than to receive. Eventually I found a place for myself in helping with music." Freeman meant by this that she did not respond to the ordinary fund-raisers' petitions: "So many people with means have a kind of museum mentality. But I couldn't care less for buildings, buildings, buildings! Patrons like to see their names on walls, so it's often easy to get support for putting up some new edifice. My passion is for the music and the composers."

The origin of this unusual enthusiasm was via the contemporary art world. Freeman was a collector, who also had a friendship with R.B. Kitaj; in the 1960s she even wrote books about the American artists Sam Francis and Clyfford Still (though neither were published: the Francis coincided with another book on the painter; and Still rescinded his permission to quote from his letters). John Cage, with a foot in the art world, seems to have been the first composer she met.

Then, in 1964, she came upon the one-time hobo, composer and instrument-maker Harry Partch. Freeman had heard his strange music, combining his microtonal "just intonation" with speech, on an LP and admired it: "And then I met this remarkable man. At the time he was so poor, he had been living in his car for six weeks. I couldn't not help him and just let him die. And so I did what I could to keep him going for the last 10 years of his life." In 1972 she produced a film about him, called The Dreamer that Remains.

"I've always been like an Indian, with one ear to the ground, curious about what's going on," she said: "At a time when Phil Glass was driving a taxi and his wife had a soup kitchen in SoHo, I was helping a lot of composers – John Cage, Lou Harrison, La Monte Young, and later Steve Reich". As her composers became better known, she supported them when they got commissions, but "pretty soon I learned that it wasn't enough to commission or compose the piece. There had to be performances, so it didn't end up just being played in a studio." So in the 1970s she adjusted her giving, commissioning pieces "only for performances by a specific ensemble or orchestra or opera company".

Her secret was that she not only liked the company of composers, she also liked their music, no matter how difficult the public found their work. She claimed to "go to concerts as often as possible, but only when there is a piece I've never heard", and she tried to go six or seven times to every one of the new pieces.

We met at the Salzburg Festival, where many of her commissions were first heard when Gérard Mortier was the director, and which I covered each summer for the Wall Street Journal. I remember I was alarmed when Betty told me she would not be staying for the second half of a particularly ravishing recital at the Mozarteum, because "I've heard those Schubert songs so often". We had splendid times together, with good talk and a lot of laughter, exploring Salzburg's restaurants.

Her second husband hated contemporary music and "only liked Verdi and Rossini. But he insisted on going to every concert with me." For several years they hosted musical soirées at their Beverly Hills house. Freeman invited two composers, who would each speak for 15 minutes, illustrating the talk with music, followed by questions. "Since he didn't like the music, my husband stayed in the kitchen. He would make pasta for 100 people." After his death in 1991 she tried to carry on the series for a couple of years, but ended it on its 10th anniversary.

Freeman had decided tastes. She commissioned Kaija Saariaho's opera L'amour de loin for Salzburg in 2000 (it will have its UK premiere at English National Opera this July), and at the press performance told me that when she first heard it in rehearsal she didn't like it – "too pretty, too sweet". She came around to it after her sixth hearing. She recognised that "contemporary music demands a lot from us. You must use your mind to ask what the composer is doing".

Betty Wishnick, photographer and philanthropist: born Chicago 2 June 1921; married firstly Stanley Freeman (two sons, two daughters; marriage dissolved), secondly Franco Assetto (died 1991); died Los Angeles 4 January 2009.