Publishers – A
- A & C Black
- A Piacere
- A-R Editions
- Aaron Publications
- ABC Verlag Zürich
- Abingdon Press
- ABRSM Archive
- ABRSM Publishing
- Academy Music Publications
- Acanthus Music
- Accent On Music
- Accolade Musikverlag
- Acoustic Music
- Activist Music
- Acuff Rose
- Acuta Music
- Acutab Publications
- ADG Productions
- Adlais
- Advance Music
- Aebersold Publications
- African Percussion
- Agape
- Agostini
- Aiora Press
- Alan Simmons Music
- Alaw Music
- Albadoc
- Alea Publishing
- Alfred Lengnick
- Alfred Publishing
- Alfredo Rolando Ortiz
- Alias Press
- All Music Publishing & Distribution
- Allans Publishing
- Allegro Publishing
- Alpha Books
- Alpha Editions
- Alphonse Leduc
- Alry Publications
- Alsbach-Educa
- AMA Verlag
- Amadeus Music
- Amadeus Press
- American Composers Forum
- Amphion
- Amsco Publications
- Amstel Music
- Andrew Green
- Anglo Music
- Annie Bank Edition
- Antico Edition
- Antoni
- Apollo Verlag
- Applause Books
- Arco Music Publishing
- Ardito
- Arion (Bosworth)
- Armelin Musica
- Arranger's Publishing Company
- Arrangetto Muziekprodukties
- Arrensdorff Edition
- Arriba!
- Ars Nova
- Ars Viva
- Art of Sound Music
- ArtistPro
- Artists Ahead Musikverlag
- Artists House
- Ascolta Music Publishing Houten
- Ashgate Publishing
- Ashley Publications
- Associated Music Publishers
- Association of English Singers & Speakers
- Astoria Verlag
- Astute Music
- Atlantic Books
- Atlantic Music
- ATV Music
- Aurea Capra Editions
- Aureole Editions
- Autopress Education
- AVID Technology
- Awkward Fermata Press