Calixa Lavallée (1842–1891) was a Canadian composer and conductor, primarily known for his contributions to classical music and choral works. Born in Verchères, Quebec, he studied music in various places, including Paris, where he gained prominence. Lavallée is best known for composing "O Canada," which was originally written as a patriotic song in 1880 and later became the national anthem of Canada. His work predominantly falls within the classical genre, with a focus on choral music, operatic compositions, and symphonic works. Notable pieces include "La chasse-galerie," a folk-inspired opera based on a popular French-Canadian legend, and various instrumental and vocal works that exhibit his deep understanding of Canadian folk themes. Lavallée's impact on music lies in his role in popularizing Canadian nationalism through music, encouraging a sense of identity and pride among Canadians during a time of growing national consciousness. His legacy continues to be recognized, particularly in Canada, where "O Canada" is celebrated as a symbol of national unity and pride.