The Pro Arte String Quartet is a string quartet founded in Belgium, which became affiliated with the University of Wisconsin-Madison in 1941.
The Pro Arte String Quartet was founded by Alphonse Onnou in Brussels in 1912. After becoming the Court Quartet to Queen Elizabeth of Belgium, the quartet began the first of many international tours in 1919. After the First World War it became famous for the performance of modern music and for its extensive recordings of Haydn. The composers Bartók, Milhaud and Honegger entrusted to the ensemble new works to premiere. The Pro Arte Quartet made its American debut in 1926 in New York and returned for 30 tours to the United States, often under the auspices of the chamber music patron Elizabeth Sprague Coolidge. It performed at the inauguration of the Hall of Music at the Library of Congress in Washington, DC. In 1932 it was named the "Quatuor de la Cour de Belgique". Its first visit to Madison, Wisconsin was in 1938. Two years later, the musicians were stranded in Madison by the outbreak of World War II and accepted a residency at the University of Wisconsin–Madison, the first such residency at a major American university.
The Royal Conservatory of Brussels holds a comprehensive collection of autograph and printed Second Violin scores from Laurent Halleux, who joined the Pro Arte Quartet when he was only fifteen and stayed with the group till 1943. It sheds light on the works performed by the quartet, especially from American composers from the early XXe s. such as Aaron Copland, Roy Harris or Louis Gruenberg.