a
- Absolute music
- absolute time
- absorption
- AC-3
- Academy curve
- Accelerando
- Accented passing tone
- Acciaccatura
- Accidental
- Accompaniment
- ACID test
- acoustic feedback
- Acoustics
- acoustic treatment
- acronym
- active crossover
- Adagio
- adapter
- adaptive differential pulse code modulation
- ADAT
- ADC, A/D converter
- Added-note chord
- Added values
- additive color mixing
- Additive rhythm
- additive synthesis
- Additive synthesis
- address
- address code
- ADPCM
- ADR
- ADSR
- Advanced Research Projects Agency
- Advanced Video Coding
- AES3 interface
- AES Standards
- AF
- AFL
- after-fade listen
- AGC
- Aggregate
- Agogic accent
- AIFF
- a-law
- Aleatoric
- Al fine
- aliasing
- alignment
- Alla breve
- Allargando
- Allegro
- All-interval row
- Al segno
- alternating current (AC)
- American Federation of Musicians
- Ametric
- ampere
- amplifier
- amplifier classes
- amplify
- amplitude modulation (AM)
- analog
- Analog synthesis
- analog-to-digital converter
- anchor
- Andante
- Anhemitonic pentatonic scale
- anonymous FTP
- Answer
- anti-aliasing
- Anticipation (ANT)
- Antiphon
- Antiphonal
- Apache
- apparent power
- applet
- Applied dominant
- Appoggiatura (APP)
- A&R
- Arch form
- ARPA
- Arpeggio
- Arranger
- Articulation
- artifact
- Artist
- Artist management
- Ascending
- ASIO
- aspect ratio
- Assignment
- Asymmetric meter
- A tempo
- Atonality
- attenuate
- attenuator pad
- audio cable
- audio coding-3
- audio frequency
- audiographics
- Audio Interchange File Format
- audio stream input/output
- Augmentation
- Augmented interval
- Augmented triad
- Aural
- Authentic modes
- Automatic Dialog Replacement
- automatic gain control
- Auxiliary tone
- AVC