A
- A Chair With Wheels
- The Abaddyon Project
- Abbfinoosty
- A.C.T.
- Acuity
- Adachi Brothers
- Adagio
- Steve Adams
- Advent
- Aeolus
- Aemen
- after@all
- After...
- Ageness
- Agent Cooper
- Ainur
- Aisles
- Jan Akkerman
- Alamaailman Vasarat
- Alaska
- Alias Eye
- Alquin
- Altair
- Alucarda
- Always Almost
- Amoeba/Robert Rich
- Amon Duul 2
- Amon Ra
- Anekdoten
- Anekdoten (England)
- Ange
- Anglagard
- Anima Dominum
- Anoxie
- Antropophobia
- Apogee
- Arabesque
- Aragon
- Arashk
- Archetype
- Arena
- Arion
- Ars Nova
- Arti E Mestieri
- Artifex
- Art Rock Circus
- Arthur Ellis 2000
- Asgard
- AshWave
- Asia
- (Original) Asia
- At Vance
- Aton's
- Audiac
- Audio Warfare
- Aurora Lunare
- The Aurora Project
- Aviary
- Ayreon
- Azazello