CCO was founded in 1984 and was the first Lesbian/Gay/Gay Positive orchestra in the world. Since then other LGBT orchestras have been founded. Here are some links:
Atlanta Philharmonic Orchestra – Atlanta, USA
Bay Area Rainbow Symphony - San Francisco, U.S.A.
Birmingham Gay Symphony Orchestra - Birmingham, U.K.
Concentus Alius Homophilharmonisches Kammerorchester - Berlin, Germany
Lakeside Pride – Chicago, USA
Les Concerts Gais - Paris, France
London Gay Symphony Orchestra - London, England
Minnesota Philharmonic Orchestra - Minneapolis, U.S.A
Queer Urban Orchestra – New York, USA
Rainbow Symphony Cologne - Cologne, Germany
Rainbow Symphony Orchestra - Paris, France
Edmonton Vocal Minority - Edmonton, Canada
Extravaganza, ensemble vocal de Montreal - Montreal, Canada
Forte, The Toronto Men's Chorus - Toronto, Canada
Gloria, Dublin's Lesbian & Gay Choir - Dublin, Ireland
Lesbian & Gay Chorus SF - San Francisco, U.S.A.
London Gay Men's Chorus - London, U.K.
London Gay Symphonic Winds - London, U.K.
Manchester L & G Chorus - Manchester, U.K.
NYC Gay Men's Chorus - New York, U.S.A.
Out in Harmony - Vancouver, Canada
Rainbow Chorus of Waterloo-Wellington - Guelph, Canada
Rainbow Harmony Project - Winnipeg, Canada
Rainbow Voices of Toronto - Toronto, Canada
Singing Out - Toronto, Canada
Vancouver Men's Chorus - Vancouver, Canada
Queer Urban Orchestra