- Aalborg Universitets Kammerkor
- Aarhus Girls Choir
- Aarhus Kammerkor
- Aarhus Pigekor
- Aashish Muralikrishnan
- Academia de li Musici
- Academy Chamber Choir of Uppsala
- Academy of Ancient Music
- Academy of Russian Music Chamber Choir
- Academy of St Martin in the Fields
- Accademia Barocca Lucernensis
- Accentus
- Accord Treble Choir
- ACDA Gospel Choir
- ACDA Western Division High School Honor Choir
- ACDA Western Division Junior High School Honor Choir
- Adalbert Kraus
- Adam Mickiewicz University Academic Choir
- Agnes Giebel
- Agnieszka Budzinska-Bennett
- Agnieszka Frankow-Zelazny
- Agrupación Coral " Amigos del Mar "
- Akademie für Alte Musik Berlin
- Akademisk Kor
- Akademisk Kor Århus
- Akademski Zbor Ivan Goran Kovačić
- Akateeminen Mieskuoro Psaldo
- Ake Leven
- Akordo
- Alamire
- Alan Raines
- Albalonga
- Albertville Centerstage Show Choir
- Aldine Children's Honor Choir
- Aleksander Kunach
- Alessandra Marc
- Alessandro Stradella Consort
- Alex Hill
- Alex Woolf
- Alexander Campkin
- Alexander Hawkins
- Alexander Lazarev
- Alexander Manotskov
- Alexander Ruth
- Alexander W. Dreyfoos School of the Arts Singers
- Alexander Yurlov Russian State Academic Choir
- Alexandrov Ensemble
- Alfred Walter
- Alfreda Hodgson
- Alice Foccroulle
- Alison Hargan
- Alissa Rose
- All Angels
- All State H.S. Women's Choir
- All State M.S. Boy’s Choir
- All-Collegiate Choir
- All-Eastern Honors Mixed Chorus
- All-Eastern Honors Treble Voice Chorus
- All-National Mixed Choir
- All-Northwest Treble Choir
- All-State Children's Choir
- All-State Children’s Chorus
- All-State Choir
- All-State Chorus
- All-State Elementary Choir
- All-State Elementary Chorus
- All-State Elementary Honors Choir
- All-State H.S. Band
- All-State H.S. Treble Choir
- All-State High School Mixed Choir
- All-State High School Women’s Choir
- All-State Honor Choir
- All-State Jazz Band
- All-State Jazz Choir
- All-State M.S. Treble Choir
- All-State Middle School Boy’s Choir
- All-State Middle School Mixed Choir
- All-State Mixed Choir
- All-State Orchestra
- All-State Small School Mixed Choir
- All-State Symphonic Choir
- All-State Tenor-Bass Choir
- All-State Texas Two-Year College Choir
- All-State Treble Choir
- All-State Treble Chorus
- All-State Women's Honor Choir
- Allabastrina Choir
- Allan Høier
- Allmänna Sången
- Alwyn Mellor
- Amadeus Choir
- Amadeus-Chor
- Amarcord
- American Boychoir
- American Repertory Singers
- Ames Chamber Artists
- Amherst College Glee Club
- Amici Chor
- Amor Artis Chorus
- Ana Fernández-Vega
- Anahit Papayan
- Anam Cara
- Anatoly Grindenko
- Anders Eby
- Andor Ilona Leánykórusa
- Andrea Donati
- Andrea Lauren Brown
- Andrea Licata
- Andreas Reize
- Andreas Schmidt
- Andreas Schmittberger
- Andreas Wolf
- Andrew Carwood
- Andrew Larson
- Andrew Lloyd Webber
- Andrew Nethsingha
- Andrew Wilson
- André Isoir
- André Previn
- Angelica Cantanti Youth Choirs
- Angelo Ephrikian
- Angleton High School Bella Voce
- Ani V'Ata
- Ankeny High School Concert Choir
- Ann Arbor Pioneer H.S. A Capella Choir
- Ann-Christine Larsson
- Anna Maria Friman
- Anna Stéphany
- Anne Johansson
- Anne Sofie von Otter
- Anne-Aurore Cochet
- Anney Barrett
- Annika Hudak
- Anonymous 4
- Ansambel Gembira
- Ansan City Choir
- Antal Doráti
- Anthony Paratore
- Antal Doráti
- Anthony Paratore
- Anthony Rolfe-Johnson
- Antioch Chamber Ensemble
- Antiphon
- Antoine Guerber
- Anton Fink
- Anton Webern Choir of Freiburg
- Antonello Rizzella
- Antonii Baryshevskyi
- Antonio Eros Negri
- Antonio Jesús Asiáin Sanz
- Antonio Juanas
- Antonio Pappano
- Antony Pitts
- Antony Walker
- Antonín Tučapský
- Ants Soots
- Anzor Erkomaishvili
- Anúna
- Appalachian State University University Singers
- Appleton Boy Choir
- Aquarius
- Aradia Ensemble
- Arbor Creek Middle School Bel Canto
- Arcanabyss
- Arcangelo
- Archikatedralny Chór Męski Cantores Minores
- Arcis-Vocalisten Munich
- Ardingly College Schola Cantorum
- Ardú
- Aric Prentice
- Arlington High School Colt Chorale Varsity Men
- Arnaud Dumond
- Arne Nordheim
- Arnold Schoenberg Chor
- Ars Cantica Choir
- Ars Nova
- Ars Nova Copenhagen
- Ars Veritas
- Arsys
- Art'n'Voices
- Arthur Bliss
- Artie Henry Middle School Varsity Treble Choir
- Artists of Valley Entertainment
- Arturo Toscanini
- Asbury University Women’s Choir
- Ashley Stafford
- Asko Ensemble
- Asociacion Coral Lagun Onak
- Aspiration in Harmony
- Atascocita High School A Cappella Choir
- Athesinus Consort Berlin
- Atlanta Master Chorale
- Atlanta Senfoni Orkestrası
- Atlanta Symphony Orchestra
- Atlanta Women’s Chorus
- Audi Jugendchorakademie
- Audra McDonald
- Augsburger Domsingknaben
- Augusta Lees
- Augustana Choir
- Aura Musicale Budapest
- Australian Brandenburg Orchestra
- Australian Chamber Choir
- Australian Rosny Children's Choir
- Australian World Orchestra
- Avner Itai