World Singing Day: worldsingingday.org/ Founded in 2012 by Colorado (USA) musician Scott Johnson, World Singing Day brings people together in their communities all around the world through the simple act of singing together.
Other Barbershop Organizations
The Barbershop Harmony Society: www.barbershop.org/ Formerly the Society for the Preservation and Encouragement of Barbershop Quartet Singing in America - SPEBSQSA - once an all-male organization of barbershop singers, who now accept both men and women.
Sweet Adelines International: www.sweetadelineintl.org/ A worldwide organization of women singers committed to advancing the musical art form of barbershop harmony through education and performances.
Ladies Association of British Barbershop Singers (LABBS): www.labbs.org.uk/ LABBS is a thriving, fun-loving, educational Association of British ladies barbershop singers in the UK.
Mixed Barbershop Harmony Association (MBHA): www.mixedbarbershop.org/ Established in 2014, the Mixed Barbershop Harmony Association exists to promote, encourage, and celebrate mixed-voice barbershop harmony in North America. Since 2018, Harmony, Inc. has partnered with MBHA to provide mixed quartets an opportunity to perform at Harmony Area Convention and Contests in order to experience Harmony's uniquely welcoming culture, receive coaching and education, and potentially post a qualifying score to represent North America on the world stage at the World Mixed Harmony Contest hosted by Barbershop in Germany (BinG!).
Primarily A Cappella: www.singers.com/ Dedicated to the discovery, dissemination, and celebration of the best vocal music from around the globe.
Harmonize.com: harmonize.com/ Free webspace provider for Barbershop groups.
HarmonySite: www.harmonysite.com/ HarmonySite is an all-in-one group-management package for your choir, club, orchestra, society, etc – bundled into your own gorgeous website. It's a public-facing website, a powerful Members Area, and an integrated Email/SMS communications tool.
Groupanizer: www.groupanizer.com "We make websites that help choirs, choruses, and music groups manage and organize themselves while creating a great public presence."