Involve the community - A good promotional idea is to include a local high school, community or collegiate choir, vocal jazz group etc as the opening act or even better to have the headliner group send the charts of a couple of their songs in advance and have the community group learn the songs and accompany the group for a few songs on stage. This ensures the support of friends, fans and family of that group and the teacher is always pleased for their group to be sharing the stage with a professional group. The King's Singers have been doing this for years to great success. The Harmony Sweepstakes A Cappella Festival , with events around the country, is now in its 17th year and consistently sells out. The A Cappella Summit has become immensely popular and has grown every year.
Many groups also teach daytime workshops and seminars which are a popular addition to an event.
Advice on presenting the event. Getting the word out to the a cappella fans by e-mail lists, newsgroups and other internet resourses. Provide a template press release and other promotional materials. Recent articles on a cappella in major newspapers.