Berlin
Boston area: Greater Boston Choral Consortium
British Columbia
Buffalo area: Greater Buffalo Friends of Music
Cambridge, UK
Central Massachusetts
Connecticut
Estonia
New England
New Jersey
New York City area: Vocal Area Network
New York City area: New York Choral Consortium
Ontario
Raleigh-Durham-Chapel Hill area
Rochester NY area
San Diego
San Francisco Bay area
Seattle area: Greater Seattle Choral Consortium
United Kingdom