Question: What did the man who composed the musical Sweethearts for Christie MacDonald participate in founding?

Context paragraphs:
MacDonald Island: MacDonald Island is part of Princess Louisa Inlet in British Columbia, between the entrance of the inlet at Malibu Rapids to the head of the inlet at Chatterbox Falls.  It is a popular mooring place for it is one of the few shallow places of the deep fjord.  The island was originally named after the man who built a cabin at Chatterbox Falls - James F. MacDonald.  In 1940 the Island was renamed Hamilton Island after Thomas F. Hamilton, who built the Malibu Club and purchased the land from MacDonald for $18,000.  In 1972 the land's name reverted to the original name of MacDonald Island.

Sweethearts (1938 film): Sweethearts is a 1938 Technicolor musical romance directed by W.S. Van Dyke, starring Jeanette MacDonald and Nelson Eddy.  The screenplay, by Dorothy Parker and Alan Campbell, uses the “play within a play” device: a contemporary Broadway production of the 1913 Victor Herbert operetta is the setting for another pair of sweethearts, the stars of the show.  This was the first color film for Nelson or Jeanette (as well as MGM's first three strip Technicolor feature).

Sharon Rich: Sharon Rich (born June 11, 1953) is an author and film historian, best known for the biography "Sweethearts" about 1930s singing stars Jeanette MacDonald and Nelson Eddy.  She was close friends for many years with Jeanette's older sister, actress Blossom Rock (aka Marie Blake).  Along with interviewing hundreds of people, Rich had access to many collections of private letters, Eddy’s personal scrapbooks, diary entries, FBI files and MacDonald’s unpublished autobiography.  As follow up documentation to "Sweethearts", Rich has written several additional books and edited and written over seventy magazine articles.  In 1995 she was awarded a Dame of Merit by the Knights of Malta for her contribution to History and Literature.

After the Show (film): After the Show is a 1921 American silent drama film directed by William C. deMille and written by Vianna Knowlton and Hazel Christie MacDonald based on a story by Rita Weiman.  The film stars Jack Holt, Lila Lee, Charles Stanton Ogle, Eve Southern, Shannon Day, and Carlton S. King.  The film was released on October 9, 1921, by Paramount Pictures.  It is not known whether the film currently survives, and it may be a lost film.

Christie MacDonald: Christie MacDonald (February 28, 1875 – July 25, 1962) was a Canadian-born American musical comedy actress and opera singer.  She was perhaps best remembered as the Princess of Bozena in the 1910 operetta "Spring Maid".  The 1913 musical "Sweethearts" was specifically written for MacDonald by composer Victor Herbert.  She retired from the stage after appearing in a 1920 revival of the musical comedy "Florodora".

D. K. C. MacDonald: Dr David Keith Chalmers MacDonald FRS FRSE FRSC (1920-1963) was a 20th century Scottish-born metal physicist, cryogenecist and scientific author.  He was one of the founding fathers of modern cryogenics.  He was of a very nervous disposition and had a morbid fear of moths.  The MacDonald Memorial Lecture at the University of Manitoba is named in his honour.  In authorship he is known as D. K. C. MacDonald, friends knew him as Keith MacDonald.

Victor Herbert: Victor August Herbert (February 1, 1859 – May 26, 1924) was an Irish-born, German-raised American composer, cellist and conductor.  Although Herbert enjoyed important careers as a cello soloist and conductor, he is best known for composing many successful operettas that premiered on Broadway from the 1890s to World War I.  He was also prominent among the tin pan alley composers and was later a founder of the American Society of Composers, Authors, and Publishers (ASCAP).  A prolific composer, Herbert produced two operas, a cantata, 43 operettas, incidental music to 10 plays, 31 compositions for orchestra, nine band compositions, nine cello compositions, five violin compositions with piano or orchestra, 22 piano compositions and numerous songs, choral compositions and orchestrations of works by other composers, among other music.

Ottawa Macdonald–Cartier International Airport: Ottawa/Macdonald–Cartier International Airport or Macdonald–Cartier International Airport ("L'aéroport international Macdonald-Cartier" in French), (IATA: YOW, ICAO: CYOW) in Ottawa, Ontario, Canada is an international airport named after the Canadian statesmen and two of the "founding fathers of Canada", Sir John A. Macdonald and Sir George-Étienne Cartier.  Located in the south end of the city, 5.5 NM south of downtown Ottawa, it is Canada's sixth-busiest airport and Ontario's second-busiest airport by airline passenger traffic and Canada's seventh-busiest by aircraft movements, with 4,743,091 passengers and 153,347 aircraft movements in 2016.  The airport is an Air Canada focus city and the home base for First Air.  The airport is classified as an airport of entry by Nav Canada and is staffed by the Canada Border Services Agency.  The airport is one of eight Canadian airports that have United States border preclearance facilities.  The airport used to be a military base known as CFB Ottawa South/CFB Uplands.  Although it is no longer a Canadian Forces Base it is still home to the Royal Canadian Air Force's 412 Transport Squadron.

Sweethearts (book): Sweethearts: The Timeless Love Affair On screen and Off Between Jeanette MacDonald and Nelson Eddy is biographical book by Sharon Rich.  First published in hardback in 1994 by Donald I. Fine, Inc., the book covers the relationship of Jeanette MacDonald and Nelson Eddy.  Rich drew heavily on Eddy's mother, who had kept Eddy's diaries and letters.

Rod MacDonald: Rod MacDonald (born August 17, 1948) is an American singer-songwriter, novelist, and educator.  He was a "big part of the 1980s folk revival in Greenwich Village clubs", performing at the Speakeasy, The Bottom Line, Folk City, and the Songwriter's Exchange at the Cornelia Street Cafe for many years.  He co-founded the Greenwich Village Folk Festival.  He is perhaps best known for his songs "American Jerusalem", about the "contrast between the rich and the poor in Manhattan" ("Sing Out! "), "A Sailor's Prayer", "Coming of the Snow", "Every Living Thing", and "My Neighbors in Delray", a description of the September 11 hijackers' last days in Delray Beach, Florida, where MacDonald has lived since 1995.  His songs have been covered by Dave Van Ronk, Shawn Colvin, Four Bitchin' Babes, Jonathan Edwards, Garnet Rogers, Joe Jencks, and others.  His 1985 recording "White Buffalo" is dedicated to Lakota Sioux ceremonial chief and healer Frank Fools Crow, whom he visited in 1981 and 1985, and who appears with MacDonald in the cover photograph.  Since 1995 MacDonald has lived in south Florida, where his cd, "Later that Night" was named "Best Local Cd of 2014" by "The Palm Beach Post" and reached the top ten in national folk music charts.  His first novel, The Open Mike, about a young man in the open mike scene of Greenwich Village, was published on December 5, 2014, by Archway Publishing.

Supporting paragraphs: Christie MacDonald Victor Herbert
Answer: American Society of Composers, Authors, and Publishers