International Jazz Day takes place on April 30, 2019. International Jazz Day is a yearly event organized by UNESCO to celebrate “the virtues of jazz as an educational tool, and a force for peace, unity, dialogue and enhanced cooperation among people.”
Jazz is a music that originated at the beginning of the 20th century within the African-American communities of the Southern United States. Its roots lie in the African-American adoption of European harmony and form to existing African musical elements. African musical influences are evident in the use of blue notes, improvisation, polyrhythms, syncopation and the swung note.
While jazz is considered difficult to define, improvisation is consistently regarded as being one of its key elements. The centrality of improvisation in jazz is attributed to its presence in influential earlier forms of music: the early blues, a form of folk music which arose in part from the work songs and field hollers of the African-American workers on plantations. (With material from: Wikipedia)