Jazz has given rhythm to the struggles of civil rights movements around the world, the top UN cultural official said on Wednesday, hailing the power of the music to bring together artists from different cultures and backgrounds as a driver of integration and mutual respect. "Through jazz, millions of people have sung and still sing today their desire for freedom, tolerance and human dignity," the director-general of the UN Educational, Scientific and Cultural Organization (UNESCO), Irina Bokova, said in her message for International Jazz Day, celebrated each year on April 30. International Jazz Day, proclaimed during the UNESCO General Conference in November 2011, is a yearly event to celebrate "the virtues of jazz as an educational tool, and a force for peace, unity, dialogue and enhanced cooperation among people." The first annual International Jazz Day was kicked off in Paris by Bokova and UNESCO Goodwill Ambassador Herbie Hancock. Born in the United States at the beginning of the 20th century, jazz is rooted in African traditions, draws from European musical forms, and has evolved into various styles across the globe. But as Hancock puts it, "the roots of jazz are in humanity." "Music, and jazz in particular, is an international language that represents freedom because of its origin -- growing out of slavery," Hancock was quoted by the UN News Center as saying. This year's celebration of jazz coincides with the 20th anniversary of UNESCO Slave Route Project, consecrated to the theme, "Assume the past, understand the present, build the future together." Since its launch in Benin in 1994, the project has aimed to break the silence surrounding the slave trade and slavery, and contribute to a culture of peace. "Music is such a beautiful way to tell stories. And in my mind, the stories we need to tell are the ones that depict the human struggle for dignity and equality," said the spokesperson for the Slave Route Project, UNESCO Artist for Peace and jazz musician, Marcus Miller. The main event for this year's International Jazz Day takes place in Osaka, which in the early 1920s was considered as "Japan' s jazz mecca." Its key early figures in jazz include composer Hattori Ryoichi and trumpeter Nanri Fumio, who Louis Armstrong nicknamed the "Satchmo of Japan." "With its numerous jazz clubs and its world-renowned annual ( jazz) competition, Osaka is the heart of the modern jazz movement, " Bokova said. The Day kicked off with a series of jazz education programs, performances, and community outreach, culminating in an internationally broadcast concert from Osaka Castle Park headlined by Hancock. The line-up also includes Wayne Shorter, Kenny Garrett, Terumasa Hino, Dee Dee Bridgewater and Miller, among others. "Each of the past two International Jazz Day celebrations reached more than one billion people through jazz performances, education and outreach programs, and media," said Tom Carter, president of the Thelonious Monk Institute of Jazz, UNESCO's ongoing partner for the Day. "This is a phenomenal figure and we believe even more people will participate in 2014," Carter said. Coinciding with this year's Day, the UN Postal Administration ( UNPA) is issuing postage stamps and a souvenir card. Designed by UNPA Art Director Sergio Baradat, the stamps will be issued in U.S. dollars, Swiss francs and euros.