http://www.casa.org/ambassadors.html Groups, concert dates, albums, tips and advice, news, reviews, more. http://www.a-cappella.com Purchase hard to find a cappella items: CDs, video, songbooks, and merchandise. Home and producer of the National Championship of Collegiate A cappella and also the Best of Collegiate A cappella recordings. http://www.singers.com Dedicated to the discovery, dissemination and celebration of the best a cappella vocal music from around the globe. http://www.rarb.org/ Reviews of a cappella albums, done by independent expert reviewers. http://www.acappellafoundation.org/ Non-profit organization whose goal is to spread the joy of a cappella music. http://home2.planetinternet.be/jrondas/E_a_capella_startpage.htm Dedicated a cappella enthusiast offers news, information, reviews, artist details, commentary and links. http://www.casa.org/ A non-profit membership organization formed in 1990 to foster and promote a cappella music. St. Paul, MN.