Amici
- Formed in 1995, Amici (Italian for friends) is an ensemble of singers and instrumentalists based in North-West England who regularly perform both a cappella as a chamber choir and with orchestra.
- http://homepage.ntlworld.com/bayreuth/amici/

Aire Valley Singers
- A 30+ voice chamber choir based in Shipley, West Yorkshire, England, with a wide repertoire of music of all styles and ages. Concerts, recordings, and music director. Please visit our new website, where you can find out about us, see us and listen to us
- http://www.airevalleysingers.co.uk/

Adelaide Chamber Singers
- Based in Adelaide, South Australia, and directed by conductor Carl Crossin, this small group of singers specialises in Australian contemporary and early european music. Concerts, recordings, and choir information.
- http://www.adelaidechambersingers.com/

Antioch
- A 10 member mixed vocal ensemble based out of Trinity Church Wall Street(NYC) that perform repertoire from the Renaissance to the present.
- http://www.antiochonline.com/

Amadeus - The Chamber Choir
- Chamber choir available for hire with a wide-ranging repertoire, from church music and madrigals to contemporary works and Broadway songs. Formby, North West of England.
- http://www.amadeus.gb.com/

Amici Chamber Choir
- The choir was founded in 1986, so that a group of enthusiastic singers could enjoy themselves while performing music to a high standard. 30 singers, based in North Harrow, England.
- http://www.amicichamberchoir.org.uk/