http://www.queensoratorio.org/why-choruses-matter/

http://www.slate.com/articles/life/culturebox/2013/07/singing_in_a_choir_research_shows_it_increases_happiness.html

http://ideas.time.com/2013/08/16/singing-changes-your-brain/

http://theconversation.com/choir-singing-improves-health-happiness-and-is-the-perfect-icebreaker-47619

http://www.dummies.com/how-to/content/the-benefits-of-singing-in-the-choir.html